Oil-in-water emulsion containing C10-C24 fatty acid derivatives for treating skin of mammals

ABSTRACT

An oil-in-water emulsion for application on a skin surface is disclosed. The emulsion comprises an oily phase and an aqueous phase. The oily phase comprises a first lipid of vegetable or animal origin. The emulsion is stabilized by containing at least one surfactant/emulsifier. The surfactant/emulsifier is substantially removed from a skin surface onto which the emulsion has been applied and from the emulsion by flushing with a liquid, thereby leaving at least a part of the oily phase on the skin. When the emulsion is diluted with tap water, which has a degree of hardness of about 18 degrees in a volume of 100 parts of water to one part of the emulsion at ambient temperature, it is separated into at least two distinct phases after standing for 24 hours at ambient temperature. The emulsion has a pH value of at least about 6 and at least about 50% w/w of the total concentration of the surfactant/emulsifier which is a fatty acid derivative. The fatty acid derivative has a fatty acid component which is a saturated or unsaturated C 10 -C 24  hydrocarbon carboxylic acid or mixtures thereof. The emulsion can be used in a method for cleansing or conditioning a skin surface, for treating human skin, for treating mammals against parasites belonging to the phylum Arthropoda and for protecting human skin against the sun.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an oil-in-water emulsion, especially for use onmammalian skin, in particular on human skin, or hair in order to cleansethe skin or hair, remove dirt, etc., and/or to preserve or improve thecondition of the skin, and/or to prevent or treat various skinconditions such as, e.g., dry skin, irritated skin or otherwisetraumatized skin. Upon application on a skin surface and followingrinsing or flushing the skin surface with a liquid, the oil-in-wateremulsion separates into at least two distinct phases and leaves aprotective layer on the skin comprising at least a part of the oilyphase.

An oil-in-water emulsion according to the invention also has usefulproperties with respect to protection of the skin against sun light andwith respect to combatting attack from parasites like lice, fleas andscabies on mammals such as humans, domestic animals and pets. Thus, inother aspects of the invention it relates to a method for combattingattack from such parasites by administering an effective amount of anoil-in-water emulsion.

In other aspects the invention relates to a method for cleansing,conditioning or treating the skin by application of an oil-in-wateremulsion. Furthermore, the invention relates to a skin-friendly lipid,namely Meadowfoam seed oil, as a therapeutic agent, and as an agentwhich in itself in synergistic effect with other constituents iseffective against mammalian parasites, especially from the phylumArthropoda, and as an agent which is effective as a sun screen or aUV-A, UV-B or UV-C filter.

2. Description of Related Art

In many industrial activities and during household chores, it isnecessary for people to expose their skin, and especially their handsand arms, to environments wherein their skin especially on arms and/orhands may become soiled, stained or injured by mechanical or chemicalexposure, or the like. Furthermore, many industrial activities andhousehold chores require a high hygienic standard, particularly in thefood and medicinal industries and in hospitals.

A high hygienic standard comprises a very frequent exposure of humanskin to cleansing involving various kinds of soaps and other chemicalsin order to disinfect the skin and/or to remove soil and unwantedmicroorganisms, especially pathogenic microorganisms, from the skinsurface.

The skin may be cleansed with detergents, solvents or abrasives, singlyor in combination. Among the detergents, soaps have enjoyed the greatestofficial status. The non-soap detergents have become important, not onlyas household cleansers but also in industry and in dermatologic andsurgical practice as well.

Most persons who frequently wash and clean their skin, especially ontheir hands, very often develop a dry skin surface and, furthermore, theskin becomes irritated and rough, most likely because the barrierfunction of the skin is negatively affected by the compositions used forcleansing and washing the skin.

Despite of many years of research within the personal cleansing field,the majority of the consumers finds that the present day cleansingcompositions still need improvement with respect to a gentle and mildcleansing of the skin. Thus, the consumers normally find it necessary toapply a separate lotion or creme to the skin after using a cleansingproduct (industrial use as well as general use in the household in theform of e.g. shower or bath preparations) in order to counteract thedelipidizing and demoisturizing effect of the cleanser.

Such lotions or cremes are generally in the form of emulsions such as aan oil-in-water emulsion, i.e. with a content of tensides, surfactantsor emulsifiers in order to avoid leaving a greasy feeling uponapplication onto the skin and thereby improve user acceptance. Thelotions or cremes are rubbed into the skin leaving the ingredients,including the tensides, surfactants or emulsifiers, as a deposit on thesurface of the skin. However, tensides, surfactants and/or emulsifyingagents are generally believed to be irritative to the skin which in turnmeans that it would be highly desirable to avoid a deposit of suchagents on the skin surface after application of a topical composition(such as, e.g., a cleansing composition, a lotion, a creme, etc.). Atenside deposited on the skin is believed to partly dissolve the lipidswithin the skin; the lipids will then be removed from the skin e.g. bywashing or sweating often resulting in the development of dry skin.

In general, cleansing compositions in the form of oil-in-water emulsionsare preferred because they have a non-greasy and clean feel. However, aproblem with the present day cleansing compositions is that effectivepersonal cleansing compositions are difficult to formulate as anoil-in-water emulsion due to the fact that a surfactant/emulsifier isincorporated in the oil-in-water emulsion for storage stability reasons(i.e. to avoid phase separation during storage). The requirement ofhaving a good storage stability is, however, a drawback with regard tothe cleansing ability of the emulsion if the oil phase is held tootightly to the aqueous phase and therefore does not become availableduring the cleansing process. Furthermore, surfactants/emulsifiers whichare added to the emulsion due to their cleansing abilities can alsoreduce the cleansing effect of the emulsion because thesurfactant/emulsifier retains its effect as an emulsifier and therebyrenders both the cleansing active surfactant/emulsifier and the oilphase less available for cleansing.

Furthermore, with a view to the environment, there is a growing demandfor a general use of ingredients which are friendly to the environment,i.e. ingredients which can be degraded or decomposed by nature orotherwise degraded into harmless substances.

International patent application published under No. WO 96/32092 (TheProcter & Gamble Company) on Oct. 17, 1996, i.e. after the priority dateof the present application, relates to personal cleansing compositionscomprising acrylic salts or derivatives of acrylic acid.

U.S. Pat. No. 5,382,381 (Imperante et al.) relates to emulsionscomprising silicone bases phosphate esters.

International patent application published under No. 95/17163(Colgate-Palmolive Company) relates to a skin cleansing compositioncomprising a combination of a high-foaming and a mild-foaming substance.

European patent application published under No. 0 111 895 (HenkelKommanditgesellschaft auf Aktien) relates to a skin conditioningcomposition in the form of an emulsion. The oily component contains asmandatory constituents paraffin oil or silicon oil or a mixture thereof.

SUMMARY OF THE INVENTION

As will be apparent from the above, there is a need for the developmentof improved cosmetically acceptable compositions which can be used forcleansing a skin surface. The present invention relates to such improvedcosmetically acceptable compositions which can be used for cleansing askin surface, especially a human skin surface, and which containingredients which are safe for the environment, i.e. ingredients whichin sewage disposal plants are decomposed into substantially harmlesssubstances, and which have a protective effect on the skin (e.g. againstirritation and drying), and which have an emollient effect, and whichhave excellent cosmetic and physical stability, and which are capable ofleaving at least a part of the oil phase on the skin upon cleansing orwashing the skin surface with the composition and rinsing or flushingthe skin surface with a suitable liquid; the part of the oil phaseremaining on the skin surface after use of the composition impartsconditioning, smoothing and emollient properties to the skin and, thus,reduces the tendency to develop dry, irritated or otherwise traumatizedskin.

As it is discussed in detail below the skin-friendly effect of acomposition according to the present invention is so advantageous thatin many cases cleansing of the skin need not be followed by applicationof a moisturizing or otherwise skin conditioning conventional lotion orcreme in order to preserve the skin surface substantially intact anduntraumatized.

The novel personal cleansing compositions are in the form ofoil-in-water emulsions. Even when a natural soap is contained in theemulsions, they are surprisingly storage stable, yet have a suitable lowviscosity. Furthermore, the emulsions are easily spread on the skin,easy to dilute and to remove from the skin and to separate into twodistinct phases. The emulsions also exhibit excellent mildness andcleansing effect and at the same time significantly minimize adelipidizing effect on the skin; on the contrary—and as is explained infurther detail in the examples given herein—an emulsion according to thepresent invention provides a deposit of a lipid on the skin and,accordingly, it preserves the normal barrier function of the skin.Furthermore, the oil-in-water emulsions have an excellent ability ofbreaking into an oily and an aqueous phase upon dilution or rinsing witha suitable flushing medium such as, e.g., plain water while at the sametime exerting an excellent storage stability.

Thus, in one aspect the present invention relates to an oil-in-wateremulsion for application on a skin surface, the emulsion comprising askin-friendly oily phase and an aqueous phase,

the emulsion being stabilized by containing at least onesurfactant/emulsifier, the at least one surfactant/emulsifier beingcapable of being substantially removed from a skin surface onto whichthe emulsion has been applied and from the emulsion by flushing with aliquid, thereby leaving at least a part of the oily phase on the skin,and

the emulsion—when diluted with tap water having a degree of hardness ofabout 18 degrees in a volume of 100 parts of water to one part of theemulsion at ambient temperature—being separated into at least twodistinct phases after standing for 24 hours at ambient temperature.

As mentioned above, an oil4n-water emulsion according to the inventionleaves at least a part of the oily phase on the skin upon cleansing theskin with the oil-in-water emulsion. The at least one part of the oilyphase which remains on the skin surface covers the skin surface with athin layer acting as a protective layer against drying of the skin. Thethin layer of the at least one part of the oily phase also has asmoothing and/or emollient effect on the skin (discussed in furtherdetail below).

Therefore, an oil-in-water emulsion according to the invention isespecially suitable for use by persons who frequently wash or cleantheir skin, such as the skin on their hands or arms, for persons whoseskin surface is exposed to chemical or mechanical influences, forpersons whose skin surface or part of the skin surface becomes soilede.g. by greasy substances during work, or for persons who suffer fromdry skin or irritated skin.

Research has shown that when conventional washing or cleansing soaps aresubstituted with an emulsion according to the invention then thefollowing normal feeling of dry skin is avoided, thus reducing or eveneliminating the need for using a conditioning lotion or creme.

In general, all persons who—after washing or cleansing of the skin—findit necessary to apply a lotion, creme, or the like with someconditioning effect on the skin can advantageously make use of anemulsion according to the invention.

The skin surface onto which an oil-in-water emulsion according to theinvention is applied is a mammal skin surface, especially a human skinsurface. In the present context the term “skin surface” relates to theoutermost surface of the body and embraces intact skin as well asinjured skin surfaces, mucosa and mucous membranes. The term “skinsurface” is used in a very broad sense embracing the epidermal layer ofthe skin and—in those cases where the skin surface may be injured—alsothe dermal layer of the skin. The epidermal layer of the skin is theouter (epithelial) layer and the deeper connective tissue layer of theskin is called the dermis. The skin may have a thick or a thin epidermisand is therefore often classified as thick or thin skin. In the presentcontext, the term “skin” embraces thick skin as well as thin skin.

Thick skin is found on the palms of the hands and the soles of the feet,whereas thin skin covers the remainder of the body. The skin on thepalms of the hands and the soles of the feet has a thick epidermis witha particularly thick layer of keratin on its outer surface. The skincovering the remainder of the body has a relatively thin epidermis andthe outer keratinized layer of the epidermis is relatively thin.

DETAILED DESCRIPTION OF THE INVENTION

As mentioned above, an emulsion according to the invention separatesinto at least two distinct phases when the emulsion applied on the skinis flushed with a liquid. In principle the flushing medium can be anysuitable liquid provided that it has the ability to impart a separationof the emulsion into distinct phases. The separation of the emulsioninto at least one oily phase and at least one aqueous phase means thatthe function of at least a part of the stability-impartingsubstance/substances present in the emulsion is destroyed. Therefore,the type of liquid used as the flushing medium depends on theingredients contained in the emulsion. In general, tap water with adegree of hardness of about 8-25 degrees, such as about 15-25 degreessuch as e.g. 18 degrees, is suitable as flushing medium, but suitableliquids may also be other kinds of aqueous solutions comprising e.g.alcohols like ethanol, propanol, and isopropyl alcohol, salts, etc. Theterm “tap water” when used herein is water having a content of Ca⁺⁺ andMg⁺⁺ ions (which ions can form insoluble salts with fatty acids) andresulting in a degree of hardness of about 8-25 degrees, such as about15-25 degrees such as e.g. 18 degrees.

In order to be a suitable flushing medium, the liquid should be able todestroy or otherwise negatively influence the function of thesurfactant/emulsifier present in the emulsion, either by destroying thesurfactant/emulsifier in itself or by being able to establish a bindingto the surfactant/emulsifier which binding is stronger than the bindingbetween the surfactant/emulsifier and the oily phase. In the first case,where the surfactant/emulsifier is destroyed or the function of thesurfactant/emulsifier is otherwise negatively influenced, the functionof the surfactant/emulsifier can be destroyed e.g. by adding a liquidhaving a content of ions or other substances which are capable offorming substantially insoluble salts with the surfactant/emulsifierpresent in the emulsion. Examples of such ions are e.g. Ca⁺⁺, Mg⁺⁺, etc.The function of the surfactant/emulsifier may also be destroyed due to adilution of an additive in the emulsion leading to a degradation of thesurfactant/emulsifier. For the purpose of the present invention it isbelieved that at least about 30% w/w such as at least about 50% w/w ofthe content of the surfactant/emulsifier should be destroyed by rinsingwith a flushing medium.

As will be discussed in detail below and in the examples herein it iscontemplated that the presence of an excess of free fatty acid in anoil-in-water emulsion according to the invention contributes to an easybreaking of the emulsion when the emulsion is contacted with a suitableflushing medium. In those cases, where no or only an insufficient amountof free fatty acid is present in an emulsion according to the inventionit is therefore envisaged to obtain the same easiness in breaking theemulsion by adding a suitable amount of free fatty acid (or any othercosmetically acceptable acid) to the flushing medium. Other appropriateingredients may of course also be added to the flushing medium in orderto impart the breaking of the emulsion (e.g. salts like Ca²⁺ or Mg²⁺salts) or to obtain a beneficial effect on the skin (e.g. conditioners,flocculating agents etc.).

The suitability of a specific liquid for use as a flushing medium can bedetermined e.g. by dilution of an emulsion according to the inventionwith the specific liquid in a volume of e.g. 100 parts of water to 1part of the emulsion (this ratio seems to be closest to the ratioobtained in practice). However, other ratios may also be relevant, suchas e.g. a ratio of 10:1 or 4:1 at ambient temperature. If the emulsionhas separated into at least two distinct phases after being allowed tostand for 24 hours at ambient temperature, then the liquid might besuitable for use as a flushing medium provided that other requirementsare also fulfilled (such as e.g. a skin-friendly nature of the liquid).

Skin-friendly First Lipid

The at least one part of the oily phase which remains on the skin afterflushing with a liquid comprises a skin-friendly first lipid. The lipidis present in the emulsion in a concentration corresponding to at leastabout 1% w/w, such as e.g. at least about 2% w/w, at least about 3% w/w,at least about 4% w/w, at least about 5% w/w based on the totalemulsion, or corresponding to a range of from about 1-50% w/w such ase.g. about 2-40% w/w, about 2-35% w/w, about 2-30% w/w based on thetotal emulsion. The lipid may also be effective even in concentrationsbelow about 4% w/w.

A lipid suitable for use according to the above is a lipid which has agood adherence to the skin. A good adherence to the skin can beevidenced objectively by persons applying the lipid to the skin or,alternatively, by use of standardized methods for the evaluation ofbioadhesion. Furthermore, a lipid suitable for use according to theinvention is a lipid which is liquid or semi-solid or solid (such ase.g. lanolin) at room temperature. In some cases a lipid in liquid formis found to be the most suitable.

Other lipids which are suitable for use as a first lipid in an emulsionaccording to the invention are lipids which have such a water retentionability that 1 g of the lipid can retain at least 2 g of water atambient temperature. Relevant examples of such lipids are Meadowfoamseed oil, Shea butter (Karite butter), cocoa butter, lanolin, andmixtures thereof. Meadowfoam seed oil can retain 6 times its own weightof water and a mixture of Meadowfoam seed oil and Karite extract(available under the name FANCOL VB from Fanning Corporation, U.S.A.)can retain about 8 times its own weight of water.

The water retention ability is believed to be important in order i) tosupply moisture to the skin onto which the emulsion has been applied,and ii) to enable application of e.g. moisture absorbing or adjustingagents (e.g. urea or urea derivatives which have been dissolved orsuspended in the oily phase of the emulsion).

Apart from the above-mentioned advantages with respect to the moistureregulation of the skin, the function of the skin-friendly first lipidalone or in combination with other constituents of the oily phase of theemulsion is:

i) to enable application of oil-soluble vitamins to the skin (e.g. bydissolving the vitamin(s) in question in the oily phase of theemulsion), and

ii) to protect the barrier of the skin or to contribute to a recovery ofthe skin barrier (e.g. expressed by measuring the transepidermal waterloss (TEWL) as explained in the examples herein).

Furthermore, a useful effect has been observed with respect to exertingan effect against sun light and—when applied to or on hair—againstparasites from the phylum Arthropoda (e.g. lice, fleas, scabies, etc.),i.e. the first lipid may in itself or in combination with otherconstituents of the oily phase of the emulsion be a UV-filter or a sunscreen.

Furthermore, a deposit of a lipid on the skin (or hair) afterapplication is very advantageous because the property of an emulsionaccording to the invention can be further utilized by adding activeagents to an emulsion or oily phase of an emulsion according to theinvention. The active agent to be added must have a certain solubilityin the oily phase or it may suspended in the oily phase in order toensure that the agent is delivered to the skin or hair surface. Relevantactive agents are e.g. i) agents which protect against sun light, ii)agents which protect against external microorganisms, iii) agents whichprotect against oxygen, agents which protect against aggressivesubstances (e.g. substances in the atmospheric air, liquids and solids),iv) agents which are effective against e.g. lice, v) drug substances,and vi) agents which have a conditioning or emollient or otherwisebeneficial effect on the skin.

A lipid which has proved suitable for use in the present context is alipid which is a triglyceride comprising at least 90% of long chainC₂₀-C₂₂ fatty acids.

The long chain C₂₀-C₂₂ fatty acids may be saturated or unsaturated(mono-, di-, or triunsaturated) fatty acids.

A triglyceride comprising a combination of a monoenoic and a dienoicfatty acid component has especially proved to be suitable for theintended use. In the combination, the ratio of the monoenoic fatty acidcomponent to the dieonic fatty acid component is in a rangecorresponding to from about 1:99 to about 99:1 such as e.g. from about1:50 to about 50:1, from about 1:26 to about 25:1, from about 1:10 toabout 10:1 such as about 3:1 to about 6:1.

In a useful combination, the two unsaturated bonds of the dienoic fattyacid component is spaced from each other by at least 3 carbon atoms,such as at least 5, 6, 7, 8 or 9 carbon atoms.

A specific lipid which has proved suitable for use and which is alsoskin-friendly is triglycerides derived from plant species of the familyLimnanthaceae such as Limnanthes alba. Meadowfoam seed oil is an exampleof such a lipid.

Meadowfoam seed oil—also denoted Meadowfoam triglyceride—is very stabletowards oxidation and heat. It comprises triglycerides about 96% ofwhich are long chain C₂₀-C₂₂ fatty acids. The composition of Meadowfoamtriglyceride is:

Long chain C₂₀-C₂₂ fatty acids: 95-97%, and the approximate content oflong chain fatty acids are:

20:0 (i.e. a C₂₀ fatty acid having 0 double bonds) 0.05 20:1 (delta 5)(i.e. a C₂₀ fatty acid having 62.5 1 double bond at the 5 position) 20:1(delta 13) — 22:1 (delta 5) 2.5 22:1 (delta 13) 12 22:2 (delta 5, delta13) 18 Other (primarily C₁₈ tocopherols) 0.5

As mentioned above other specific interesting lipids for use as a firstlipid in an emulsion according to the invention are lanolin, cocoabutter and shea butter (Karite extract). In the following is given thecomposition of cocoa butter and shea butter, respectively.

Chemical constituents of shea butter and cocoa butter Fatty acid (WL %)Cocoa butter Shea butter Palmitic 24.4 5.7 Stearic 35.4 41.0 Arachidic 00 Total saturated 59.8 46.7 Oleic 38.1 49.0 Linoleic 2.1 4.3 Totalunsaturated 40.2 53.3 Glycerides (mole %) Triunsaturated 2.5 5.0Monounsaturated 52.0 — Palmitostearin Monounsaturated 8.5 — DipalmitinMonounsaturates 18.4 34.0 Distearin Diunsaturated stearin 12.0 45.0Diumsaturated palmitin 8.4 11.0 Triunsaturated 0 5.0

Physical constants of shea butter and cocoa butter Parameter Cocoabutter Shea butter Refractive index (40° C.) 1.44-1.45 1.46 Acid value1-4 2.2 Iodine value 34-38 48-60 Saponification value 200-240 160-180Melting point (° C.) 35 37-38 Polymorphic forms = 4 2 Colour GoldenStraw Yellow Odour Like chocolate Characteristic fatty smell FeelSlightly greasy Sligtly greasy Specific gravity 0.856-0.864 0.91-0.95(20° C.) Percent of 0.2-1.0 3-13 unsaponifiables

The present inventors have also found that beneficial effects areobtained when a first lipid is mixed with a vegetable extract such as,e.g. Karite butter extract and/or Karite extract. However, otherextracts are also believed to be useful in the present context e.g.extracts such as, e.g., aloe barbadensis extract, apricot extract,arnica montana extract, balm mint extract, bamboo extract, bearberryextract, beet extract, bilberry extract, birch leaf extract, blackberryleaf extract, bladderwrack extract, buckwheat extract, burdock extract,butcherbroom extract, calendula extract, carrot extract, matricariaextract, cherimoya extract, jujube extract, coltsfoot extract, comfreyextract, coneflower extract balsam copaiba, cornflower extract, cucumberextract, dog rose hips extract, fennel extract ginger extract, ginkgoextract, ginseng extract, camellia sinensis extract, guarana extract,crataegus monogina extract, hayflower extract, henna extract, hopsextract, horsetail extract, horsechestnut extract, hydrocotyl extract,ivy extract, Job's tears extract, juniperus communis extract, kiwiextract, lady's mantle extract, laminaria digitata extract, lavenderextract, lemon peel extract, licorice extract, linden extract,lithospermum officinale extract, mallow extract, mango extract,marshmallow extract, melon extract, mimosa tenuiflora bark extract,white oak bark extract, English oak extract, oyster shell extract, pansyextract, peach extract, capsicum frutescens oleoresin, capsicumfrutescens extract, peppermint extract, quillaja saponaria extract,raspberry extract, krameria triandra extract, rosemary extract, sageextract, St. John's wort extract, stinging nettle extract, strawberryextract, soapwort extract, thyme extract, walnut extract, watercressextract, wheat germ extract, willow bark extract, witch hazel extract.

With respect to the concentration of the first lipid, or wheneverrelevant in combination with an extract, in the emulsion, it isgenerally in a range corresponding to from about 1% to about 50% w/wsuch as, e.g., from about 2 to about 30% w/w, from about 1 to about 20,from about 2 to about 10.

Instead of using a lipid or mixtures of lipids in order to form aprotective layer on the skin surface, a protein or a proteinaceoussubstance may be used either alone or in admixture or in combinationwith a lipid. Vegetable protein hydrolysates (such as e.g. hydrolyzedwheat gluten (Gluadin, Tritisol), almond flour hydrolysate (GluadinAlmond)), wheat protein fatty acid condensates (such as e.g. sodiumcocoyl hydrolyzed wheat protein (Gluadin WK)) and cationic wheat proteinhydrolysates (such as e.g. laurdimonium hydroxypropyl hydrolyzed wheatprotein (Gluadin WQ)) are considered suitable for use in an emulsionaccording to the present invention. Furthermore, suitable vegetableproteins may be soybean, pea and rice protein as well as almond flour.

Surfactant/emulsifier

An emulsion according to the invention contains at least onesurfactant/emulsifier. Especially in oil-in-water emulsions intended forcleansing purposes, the at least one surfactant/emulsifier plays anactive role in the cleansing process, i.e. it has a cleansing ability initself. Furthermore, the surfactant/emulsifier imparts physicalstabilization to the emulsion so that it has an excellent storagestability.

In the present context the terms “surfactant”, “surface active agent”and “tenside” are used to denote a substance that reduces surfacetension when dissolved in water or aqueous solutions, or which reducesinterfacial tension between two liquids, or between a liquid and asolid. Three categories of surface active agents are: detergents,wetting agents, and emulsifiers.

The term “detergent” is generally defined as a substance that reducesthe surface tension of water; specifically a surface active agent whichconcentrates at oil-water interfaces, exerts emulsifying action, andthus aids in removing soils. The older and still widely used types arethe common sodium and potassium soaps of fatty acids (classified asanionic surfactants). The synthetic detergents are classified asanionic, cationic, nonionic, or amphoteric depending on their mode ofchemical action.

The term “wetting agent” is generally defined as a substance which, whenadded to water, causes it to penetrate more easily into, or to spreadover the surface of, another material by reducing the surface tension ofthe water.

The term “emulsifier” is generally defined as a substance that iscapable of lowering the interfacial tension between an oil and anaqueous phase and, thus, aids the dispersal of oil (in the case ofoil-in-water emulsions) and water (in the case of water-in-oilemulsions), respectively, into droplets of a small size and helps tomaintain the particles in a dispersed state. Emulsifiers are generallyclassified as i) proteins or carbohydrate polymers, which act by coatingthe surface of the dispersed fat or oil particles, thus preventing themfrom coalescing; such emulsifiers are sometimes also called protectivecolloids, and ii) long-chain alcohols and fatty acids, which are able toreduce the surface tension at the interface of the suspended particlesbecause of the solubility properties of their molecules. Soaps behave inthis manner, they exert cleaning action by emulsifying the oilycomponents of soils.

The term “soap” generally covers two types, namely i) a water-solublereaction product of a fatty acid ester and an alkali (such as e.g.sodium hydroxide) with glycerol as by-product (a soap is actually aspecific type of salt, the hydrogen of the fatty acid being replaced bya metal, which in ordinary soaps is usually sodium; soap lowers thesurface tension of water and thus permits emulsification of fat-bearingsoil particles; a typical soap is made by reacting sodium hydroxide witha fatty acid), and ii) heavy-metal soaps which are formed by metalsheavier than sodium (aluminium, calcium, magnesium, cobalt, lead, zinc,etc.) Heavy-metal soaps are insoluble in water.

In the present context, the term surfactant/emulsifier is used in themeaning of the above-given definitions of “a surface active agent”, “asurfactant”, “a detergent”, “a wetting agent”, “an emulsifier”, “asoap”, and/or “a tenside”.

A suitable surfactant/emulsifier for use in an emulsion according to theinvention is appropriately a substance which has suitableecotoxicological properties, i.e. a substance which either in itself orupon degradation is relatively non-toxic. Many non-soap detergents donot decompose in sewage disposal plants. Therefore, the presentinventors have focused on developing an emulsion notably a cleansinglotion based on real/natural soaps, i.e. substances which are relativelyharmless to the environment. The use of non-soap detergents makes itpossible to prepare compositions having a pH value near the pH value ofthe skin (i.e. a pH about 5-5.5) whereas the presence of natural soapsin a composition normally leads to a resulting pH of the composition toa value of at least 6, i.e. a pH which has been considered as highlyunsuitable. However, the importance of a pH about skin pH has beenoverrated and in connection with the present invention and as shown inthe Examples herein, the present inventors have shown that compositionshaving a higher pH than that of the skin are well-tolerated on the skinand, furthermore, impart conditioning of the skin. Suitable pH valuesfor the latter compositions are in a range from about 6 to about 8.6 orto about 9 such as, e.g., from about 6 to about 8, from about 7 to about8, or from about 7.2 to about 7.8.

As discussed earlier, the presence of an excess of free fatty acid inthe emulsion seems to have a positive impact on the ability of theemulsion to break. The pH should therefore be at the most about 8.6-9such as about 8.6 to about 8.8 (corresponding to an emulsion wherein nofree fatty acid is present), preferably at the most 8 such as statedabove.

Suitable surfactants/emulsifiers for use in an emulsion according to theinvention are fatty acid derivatives especially fatty acids which areneutralized to form a soap. Suitable surfactants are found among anionicand non-ionic soaps. Preferably, the surfactants/emulsifiers possessgood emulsifying properties. Examples of suitable fatty acid derivativesare sodium salts, potassium salts, ammonium salts, substituted ammoniumsalts, unsubstituted amides, amides with substituted amines includingethanolamides (such as monoethanolamides, diethanolamides andtriethanolamides), propanolamides, isopropanolamides, and mixturesthereof.

The fatty acid component of the fatty acid derivative for use in anemulsion according to the invention is typically a saturated orunsaturated C₁₀-C₂₄ hydrocarbon carboxylic acid, or mixtures thereof.

Examples of suitable saturated fatty acids are e.g. capric acid(C₁₀H₂₀O₂), undecylenic acid (C₁₁H₂₂O₂) lauric acid (C₁₂H₂₄O₂), myristicacid (C₁₄H₂₈O₂), palmitic acid (C₁₆H₄₄O₂), stearic acid (C₁₈H₃₆O₂),arachidic acid (C₂₀H₄₀O₂), behenic acid (C₂₂H₄₄O₂), and lignoceric acid(C₂₄H₄₈O₂), and mixtures thereof.

Examples of suitable mono-unsaturated fatty acids are palmitoleic acid(C₁₆H₃₀O₂), oleic acid (C₁₈H₃₄O₂), ebidic acid (C₁₈H₃₄O₂), erucic acid(C₂₂H₄₂O₂), and brassidic acid (C₂₂H₄₂O₂), and mixtures thereof.

Examples of suitable di- or triunsaturated fatty acids are linoleic acid(C₁₈H₃₂O₂) and linolenic acid (C₁₈H₃₀O₂), and mixtures thereof.

The at least one surfactant/emulsifier for use in an emulsion accordingto the invention may also be a mixture of fatty acid derivatives whereinthe fatty acid components are saturated, monounsaturated, diunsaturatedor triunsaturated, or mixtures thereof.

The at least one surfactant/emulsifier for use in an emulsion accordingto the invention can also be an anionic tenside such as a tensideselected from the group consisting of alkyl sulfates, N-acyl glutamates,acyl isethionates, alkyl sulfosuccinates, alkyl phosphate esters,ethoxylated alkyl phosphate esters, trideceth sulfates, proteincondensates, mixtures of ethoxylated alkyl sulfates, and mixturesthereof. Combinations of an anionic tenside with a non-ionic soap asthose mentioned above are of course also relevant in the presentcontext.

Furthermore, the at least one surfactant/emulsifier for use in anemulsion according to the invention may be an amphoteric tenside such asa tenside selected from the group consisting of sodium3-dodecylaminopropionate; sodium 3-dodecylaminopropane sulfonate;N-alkyltaurines; betaines including cocoamidopropyl betaine, cocodimethyl carboxymethyl betaine, lauryl dimethyl carboxy-methyl betaine,lauryl dimethyl alpha-carboxyethyl betaine, cetyl dimethyl carboxymethylbetaine, lauryl bis-(2-hydroxyethyl)carboxy methyl betaine, stearylbis-(2-hydroxypropyl)carboxymethyl betaine, oleyl dimethylgamma-carboxypropyl betaine, lauryl bis-(2-hydroxypropyl)alpha-carboxyethyl betaine, coco dimethyl sulfopropyl betaine, stearyldimethyl sulfopropyl betaine, amido betaines, amidosulfobetaines;4-[N,N-di(2-hydroxyethyl)-N-octadecyclammonio]-butane-1-carboxylate;5-[S-3-3 hydroxypropyl-S-hexadecylsulfonio]-3 hydroxypentane-1-sulfate;2-[P,P,P-diethyl-P 3,6,9trioxatetradexocyl-phosphonio]-2-hydroxypropane-1-phosphate;3-[N,N-dipropyl-N-3-dodecoxy-2-hydroxypropylammonio]-propanel-phosphonate;3-(N,N,-di-methyl-N-hexadecylammonio) propane-1-sulfonate;3-(N,N-dimethyl-N-hexadecylammonio)-2-hydroxypropane-1-sulfonate;4-(N,N-di(2-hydroxyethyl)-N-(2 hydroxydodecyl)ammonio)-butane-1-carboxylate;3-[S-ethyl-S-(3dodecoxy-2-hydroxypropyl)sulfonio]propane-1-phosphate;3-(P,P-dimethyl-P-dodecylphosphonio)-propane-1-phosphonate; and5-[N,N-di-(3-hydroxypropyl)-N-hexadecylammonio]-2-hydroxy-pentane-1-sulfate.

Normally, the concentration of the at least one surfactant/emulsifier inthe emulsion is in a range corresponding to from about 5 to about 25%w/w such as, e.g., from about 8 to about 20% w/w or from about 10 toabout 15% w/w. In the concentrations given, the at least onsurfactant/emulsifier is capable of removing dirt from the human skin.

An emulsion according to the invention may also comprise a furthersurfactant/emulsifier, i.e. a substance which aids in stabilizing theemulsion. Suitable surfactants/emulsifiers have an HLB value in a rangecorresponding to from about 4 to about 30 such as in a range of fromabout 6 to about 17.

The total concentration of surfactant/emulsifier in the emulsion is in arange corresponding to from about 5 to about 40% w/w, such as, e.g.,from about 10 to about 35% w/w or from about 15% to about 25% w/w.

Examples of suitable surfactants/emulsifiers for use in an emulsionaccording to the invention are polyoxyethylene sorbitan fatty acidmonoesters (e.g. Tween series), polyoxyethylene sorbitan fatty acidtriesters (e.g. Tween series), polyoxyethylene alkylphenol ethers (e.g.Triton X-series), polyoxyethylene fatty alcohol ethers (e.g.Cetomacrogol series; Brij series; Renex series), alkyl fatty alcoholethers (e.g. fatty alcohol ethyl ethers), polyoxyethylene fatty acidesters (e.g. Myrj series), sorbitan fatty acid monoesters (e.g. Arlaceland Span series), sorbitan fatty acid triesters (e.g. Arlacel and Spanseries), alkyl phosphate esters (e.g. Berol series), fatty acidmonoethanol amides, fatty acid diethanol amides, fatty acid amidoalkylbetaines (betaines), fatty acid amidoalkyl sulfobetaines(sulfobetaines), sulfated hydroxy-fatty acids (e.g. sulfated castor oil(“Turkish red oil”)).

Specific examples of suitable surfactants/emulsifiers indexed aftertheir HLB values are found in McCutcheon's Emulsifiers & Detergents,1990 International Edition.

Examples of suitable surfactant/emulsifiers for use in an emulsionaccording to the invention are;

Cocamide MEA

Cocamidopropyl betaine

C9-11 Pareth 6

Other interesting surfactant/emulsifiers for use in an emulsionaccording to the invention are:

Ethoxylated castor oil

Mono/diglycerides

Lanolin derived extracts of sterols and sterol esters

Ester of a polyglycerol derivative

Decaglycerin pentaoleate

Glycerol monostearate

POE (2) monostearate

Sorbitan trioleate

Calcium alkylbenzene sulfonate

Hydroxylated lanolin

Sorbitan sesquioleate

Oxyfatty acid monoglyceride

Polyethylene glycol dodecylphenol ether

Sorbitan sesquistearate

Sorbitan monooleate

Mannide monooleate

Sorbate 80/sorbitan monooleate

Ethoxylated polyoxypropylene glycols

Refined wool fat

Lanolin and lanolin alcohol

Sorbitan monostearate

Nonylphenol ethoxylate

Glycerol monostearate

POE (2) monooleate

Sorbitan monoisostearate

Sorbitan sesquioleate

Nonyl phenol ethylene oxide condensate

Sorbitan ester

Glycerol palmitic/stearic acid esters

Glycerol mono/distearate

Ethoxylated nonylphenol

POE glycerol sorbitan fatty acid ester

POE (2) stearyl alcohol

POE (2) oleyl alcohol

Polyethoxylated (2) stearyl alcohol

Polyethoxylated (2) oleyl alcohol

De-oiled lanolin

Isobutylated lanolin oil

Ethoxylated glycerol sorbitan oleostearate

POE-(6)-sorbitol beeswax derivative

POE-(20)-sorbitol beeswax derivative

Lactic acid fatty acid glyceride

Lactic acid ester of mono/diglycerides

PEG-7 hydrogenated castor oil

Diethylene glycol monooleate

Diethylene glycol monostearate

POE glycerol triricinoleate

Methyl glucoside dioleate

Sorbate 60/sorbitan monostearate

Diglyceryl monostearate

Glycerol monostearate

Sorbitan monoisostearate

Sorbitan monooleate

Polyoxyethylene nonylphenyl ether

Diethylene glycol monolaurate, SE

Block copolymer of ethylene oxide and propylene oxide

Fatty alcohol ethoxylate

Sucrose fatty acid esters

Methyl glucoside sesquistearate

Polyglyceryl-3 diisostearate

Ethoxylated triglyceride

POE (5) hydrogenated castor oil

Tetraglyceryl monooleate

Tetraglyceryl monostearate

Polyoxyethylene Isoryl ether

Sorbitan monopalmitate

Ethoxylated castor oil

Decaglycerin tristearate

Sorbitan monopalmitate

Polyoxyalkylene glycol

PEG 400 dioleate

PEG (8) distearate

PEG 200 monostearate

PEG 400 distearate

Polyoxyethylene lauryl ether

Polyethylene glycol monostearate

Polyethylene glycol nonylphenol ether

Furthermore, the present inventors have observed that a certain contentof free fatty acid in the composition (i.e. when a free fatty acid isincluded in an emulsion of the present invention, it is preferablyincluded in an excessive amount so that when the soap has been formed,then a free amount of free fatty acid is still present in the emulsion)is of importance with respect to the easiness with which the emulsionbreaks or separates into at least two distinct phases upon dilution witha suitable flushing medium like e.g. plain water. A measure of thecontent of fatty acid in an emulsion according to the invention is theacid value. The acid value of an emulsion according to the inventionshould preferably correspond to a range of from about 10 to about 60 mgKOH/g, such as, e.g., from about 20 to about 55 mg KOH/g, from about 30to about 45 mg KOH/g, from about 35 to about 40 mg KOH/g or from about36.0 to about 37.0 mg KOH/g.

With respect to stabilization of the emulsion the use of especially acombination of ricinus oil derivatives have proved to be excellent. Auseful combination is e.g. a combination of glycerinmonoricinoleate(available as Rilanit GMRO from Henkel) and a sulfated ricinus oil(available as Ttirkischrotole from Becker Chemie GmbH, Germany).

Oily Phase

The emulsion contains an oily phase. The oily phase may constitute notmore than about 50% w/w of the total emulsion such as in a rangecorresponding to about 1-50% w/w such as about 5-40% w/w, and about10-30% w/w.

The functions of the oily phase and/or its individual constituents arei) to serve as the disperse phase in an emulsion according to theinvention, ii) to contribute to a cleansing effect of an emulsionaccording to the invention (the oily phase or its constituents cansolubilize, bind and/or emulsify oily dirt etc. e.g. present on the skinand, accordingly, such oily dirt which notably is soluble in oil orlipid is easily cleansed), iii) together with the aqueous phase—tocontribute to a suitable viscosity of an emulsion according to theinvention without decreasing the storage stability of the emulsion, iv)to contribute to removal of unwanted microorganisms from the skin (orhair), and v) to contribute to removal of unwanted other substances fromthe skin or the hair such as, e.g., particles, solids, parasites.

Furthermore, the oily phase and/or its constituents contribute to adeposit of a part of the oily phase on the skin (or hair) afterapplication of an emulsion according to the invention. As discussedabove suitable agents may be incorporated in the oily phase (or in theemulsion) in order to enable application of the agent(s) to the skin (orhair). Such agents are e.g. agents which protect against UV light (e.g.organic and in-organic UV-absorbers like TiO₂ and ZnO, benzophenones,and UV-absorbers which have a synergistic effect on the skin such ase.g. natural or synthetic sunscreen boosters. Other agents may beLIPACIDES (from Seppic), bisabolol and Farnesol.

The oily phase also has a function as a diluent of the skin-friendlyfirst lipid, thus, contributing to a reduction of the production costsof an emulsion according to the invention.

The oily phase comprises a second lipid such as a mono-, di- ortriglyceride.

The second lipid of the oily phase is suitably selected from vegetablefats and animal fat and mixtures thereof. The lipid component may alsobe synthetic oils like e.g. Prisorine 2039 (isostearyl isostearate, CASNo. 41669-30-1), Prisorine 2041 (glyceryl triisostearate, CAS No.66085-00-5), Estol 3603 (glycerol tricaprylate/caprate, CAS. No.65381-09-1) and Estasan PR 8-60 (propyleneglycol dicaprylate-dicaprate,CAS No. 977060-55-1).

Examples of suitable vegetable fat are avocado oil, coconut fat, cocoabutter, rapeseed oil, maize oil, sesame oil, olive oil, soybean oil,palm oil, grape seed oil, almond oil, linseed oil, peanut oil, walnutoil, tall oil, thistle seed oil, wheat germ oil, sunflower oil,poppy-seed oil, cottonseed oil, persic oil, apricot oil, jojoba oil,castor oil, hydrogenated vegetable oils, CREMEOL PS 6, PSO, PSW, (AarhusOlie) and mixtures thereof.

A vegetable lipid derived from plant species from the familyLimnanthaceae such as Limnanthes alba has especially useful propertiesin connection with the present invention (cf. the discussion under theheading “Skin-friendly first lipid”; the other lipids mentioned asskin-friendly first lipids may of course also be suitable as secondlipids; however, for economical reasons these lipids are normally usedin an emulsion according to the invention in combination with at leastone of the synthetic oils, vegetable oils and animal fats mentionedabove. Meadowfoam seed triglyceride is extracted from Limnanthes albaand is discussed above.

Examples of suitable lipids derived from animals are fish oils, bird fat(such as e.g. Kalaya® oil derived from the emu), domestic animal (pig,cattle, sheep, goats) body fats, wool fat (lanolin), and whale oil, andmixtures thereof.

In a specific embodiment according to the invention an oil comprising atriglyceride of an saturated and relatively short-chain fatty acid(C₈-C₁₀), namely glycerol tricaprylate/caprate optionally in combinationwith CREMEOL PS 6 has proved suitable.

The concentration of the second lipid in an emulsion according to theinvention is typically in a range corresponding to from about 0.5 toabout 60% w/w such as, e.g., from about 1 to about 45% w/w, from about 2to about 40% w/w, from about 3 to about 35% w/w, from about 5% to about30% w/w, from about 7 to about 25% w/w or from about 10% to about 20%w/w.

It is believed that a combination of a first and a second lipid in anemulsion according to the invention is advantageous with respect to i)obtaining a suitable oily deposit on the skin (or hair), ii) obtaining asuitable deposit of any agent (cf. above) added to the emulsion with aview of obtaining a beneficial effect on the skin, iii) lowering theproduction costs of an emulsion according to the invention, and iv)obtaining a suitable cleansing effect including removal of unwantedtensides.

The sum concentration of the first and the second lipid in the emulsionis typically in a range corresponding to from about 1.5 to about 50% w/wsuch as, e.g., from about 3 to about 45% w/w, from about 5% to about 40%w/w, from about 7% to about 35% w/w, from about 10% to about 30% w/w orfrom about 15% to about 25% w/w.

Other Important Perspectives

With a view to the environment, an important feature of an emulsionaccording to the invention is that the emulsion can be degraded intosubstances which are relatively non-toxic to the environment. Thus, atleast a significant part of the individual components in the oily phaseand the aqueous phase have suitable ecotoxicological properties so thatformation of substances which are hazardous to the environment issubstantially minimized when the waste water containing the componentsare subjected to degradation in a purifying process, and so that thedegradation of the individual components in the purifying process isrelatively fast. The purifying process may take place in a sewagedisposal plant.

Furthermore, and also with a view to the environment, it is veryadvantageous that the emulsion upon application on the skin and flushingwith a liquid (or alternatively, that the emulsion when diluted with anappropriate liquid as discussed above) separates into an oily phase andan aqueous phase. This separation means that the oily phase can becollected in suitable oil separators whereas the aqueous phase can beled out together with waste water.

As mentioned above, an emulsion according to the invention has theability to separate into at least to separate phases. Thus, an emulsionaccording to the invention—when diluted with tap water (or anotherrelevant flushing medium) having a degree of hardness of about 8-25degrees such as about 15-25 degrees such as e.g. 18 degrees in a volumeor weight of 100 parts of water to one part of the emulsion at ambientor room temperature—is separated into at least two distinct phases afterstanding for at the most 24 hours such as e.g. 24 hours, 4 hours, 2hours, 1 hour or 30 minutes, 5 minutes, 1 minute at ambient or roomtemperature.

As documented in the Examples herein, an emulsion according to thepresent invention has a remarkably good storage stability. This findingis very positive and also surprising in that the emulsions tested arewater-in-oil emulsions having a content of natural soaps (based on afatty acid derivative). In general it has been observed that acombination of a natural soap and an oil in an oil-in-water emulsiondecreases the storage stability substantially. In this connection itshould be mentioned that an emulsion according to the invention shouldbe properly homogenized in order to secure maximum storage stability.

In the experimental section herein a number of non-invasive tests aredescribed. These tests are applicable either alone or, preferably in anycombination, for evaluating the effect of treatment of the skin and/orfor evaluating which effect an emulsion according to the invention hason skin surfaces upon use. In this connection reference is made toSerup, J., Skin Research and Technology 1995; 1: 109-114, “EEMCOguidance for the assessment of dry skin (xerosis) and ichthyosis:clinical scoring systems”, Loden, M., Skin Research and Technology 1995;1: 101-108, “Biophysical methods of providing objective documentation ofthe effects of moisturizing creams”, Hannuksela, A., and Hannuksela, M.,Contact Dermatitis, 1995, 32, 163-166, “Irritant effects of a detergentin wash and chamber tests”, and Paye, M., Van der Gaer, D. and Morrison,B. M. Jr, Skin Research and Technology 1995; 1; 123-127, “Corneometrymeasurements to evaluate skin dryness in the modified soap chambertest”.

An important feature of an emulsion according to the invention is itsability to deposit lipid on the skin onto which the emulsion has beenapplied. Thus, when the skin on the antecubital fossa (flex area ofelbow) sebum content was determined by employing a SebumeterG SM 810(Courage+Khazaka electronics GmbH, Cologne, Germany) as described inExample 7 herein, the sebumeter value after 40 washings should at leastbe the same as the starting value (in the Example 7 this value is 2).

In connection with treatment of desiccated skin or otherwise injuredskin, a measure of the effect of the treatment may be made by measuringthe transepidermal water loss. The treatment normally continues untilthe transepidermal water loss (TEWL), determined as described in theExamples, has decreased compared with the transepidermal water lossmeasured immediately before initiation of the treatment or,alternatively, compared with the transepidermal water loss measuredafter application of a conventional skin cleansing product

Furthermore, and also as described in Example 7 herein, the TEWL valueshould be of the same order of magnitude (i.e. the same value as thestarting value ±10% or 15%) after 40 washings as compared with the valuebefore any washing.

Finally, the corneometer value when tested according to Example 7 hereinshould be of the same order of magnitude (i.e. the same value as thestarting value ±10% or 15%) after 40 washings as compared with the valuebefore any washing.

An emulsion according to the invention is typically in the form of alotion. Preferably, the lotion has a viscosity corresponding to that ofliquid soaps. However, there may be situations where an emulsionaccording to the invention may be presented in the form of a creme or ashampoo.

An emulsion according to the invention has proved to be effectiveagainst lice present on humans. Thus, it is believed that the effectobserved is mainly due to the presence in the emulsion of askin-friendly first lipid possible in combination with the otherconstituents in the oily phase and possible also in combination with theat least one surfactant/emulsifier [the combination of thesurfactant/emulsifier/soap is believed to be of importance in connectionwith the cleansing ability and the ability of emulsifying oily dirt orsubstances and in connection with the ability of the emulsion to removeunwanted microorganisms or other unwanted organisms (lice etc.)]. Anemulsion according to the invention (e.g. PLUM Washing lotion asdescribed in the examples herein)—when applied to human verminous hairand left for 10 min—has proved to be capable of reducing the number ofadult lice and their eggs with at least 60% and, furthermore, it iscontemplated that application of 100% of a skin-friendly first lipid (asdefined herein) will reduce the number with at least 90%.

Especially, emulsions comprising a skin-friendly lipid such as, e.g., atriglyceride comprising at least 90% of long chain C₂₀-C₂₂ fatty acidshave proved to be effective against certain parasites. Accordingly, theinvention also relates to the use of an emulsion according to theinvention and especially to the use of a skin-friendly lipid such as,e.g., a triglyceride comprising at least 90% of long chain C₂₀-C₂₂ fattyacids for the treatment or prophylaxis of the presence of parasites suchas, e.g., lice, fleas and scabies on mammals such as humans, domesticanimals and pets. Especially, the emulsions described in Examples 1 and2 here in have proved to have therapeutic effect. This effect may be dueto only one of the ingredients or to a combination of one or more (e.g.all) of the ingredients, or it may be due to the very advantageouscleansing properties of the emulsion. At present at least Meadowfoamseed oil is believed to have effect against the relevant parasites, butthis does riot exclude that the other ingredients also may prove to beactive agents against parasites.

More specifically, an emulsion according to the invention or askin-friendly lipid as defined herein or compositions thereof can beused against parasites belonging to the phylum Arthropoda. Manyparasites are host-specific, i.e. a specific species is only found one.g. a human and not on an animal like a dog or a cat and vice versa. Inthe following the discussion is directed to human use but it is clearthat whenever relevant the statements given also apply for veterinaryuse for the treatment and/or prophylaxis of veterinary relevantparasites.

Only a few Arthropoda species play a role as parasites on humans. Manymore play a significant role as vectors for many infectious diseases.The medically most important arthropods are found in the classes Insectaand Arachnoidea. Relevant orders within the class Insecta are:Siphonaptera (fleas), Phthiraptera (lice), Diptera (mosquitos andflies), Hemiptera (bug), Hymenoptera (bees, wasps, ants), andOrthoptera. In connection with the present invention, especially the useagainst Siphonaptera, Phthiraptera and Hemiptera is considered as mostimportant.

The order Siphonaptera includes Pulicidae, more specifically the generaPulex (e.g. P. irritans), Ctenocephalides (e.g. C. canis and C. cati),and Xenopsylla (e.g. X. cheopsis).

The order Phtiraptera includes i) Mallophaga including theTrichodectidae family and more specifically the genus Trichodectes (e.g.T. canis), and ii) Anoplura including the Pediculidae family and morespecifically the genera Pediculus (e.g. P. humanus var. capitis and P.humanus var. corporis) and Phthirus (e.g. P. pubis).

The order Hemiptera includes two families, namely Cimicidae andRevuviidae. To the Cimicidae family belongs the genus Cimex (e.g. C.lectularius, C. hemipterus and C. boueti) and to the Revuviidae familybelongs the genera i) Tratoma (e.g. T. infestans and T. sanguisuga), ii)Rhodnius (e.g. R. prolixus) and iii) Panstrongylus (e.g. P. megistus).

A relevant order within the class Arachnoidea is Acarida. To the orderAcarida belong the following suborders: Ixodina (e.g. lxodidae includingthe genera Ixodes, Demacentor, Amblyomma, Hyalomma, Haemaphysalis,Rhipicephalus, and Argasinae including the genera Argas, Ornithodoros,and Otobius), Mesostigmatina (e.g. Dermanyssidae including the generaDemanyssus and Ornithonyssus), Trombidiformina (e.g. including thegenera Cheyletiella, Trombicula and Demodex), and Sarcoptiformina (e.g.including the families of Sarcoptidae [e,g, Sarcoptes and Notoedres],Psoroptidae [e.g. Psoroptes, Chorioptes and Otodectes], and Acaridae[e.g. Acarus].

An emulsion according to the invention may be used for treating anindividual suffering from one or more of the above-mentioned parasites.Most suitable, an emulsion comprises the skin-friendly lipid in aconcentration where it is effective against the parasite in question. Asuitable concentration is a concentration of at least 5% w/w such as atleast 6% w/w, at least 10% w/w, at least 15% w/w, at least 20% w/w, orat least 30% w/w. When Meadowfoam seed oil is used as the skin-friendlylipid the concentration may be in any range from 1-100% w/w as this oilis believed to be an active substance against the parasites mentionedabove. Especially, Meadowfoam seed oil has proved to be active againstall types of lice (e.g. Pediculus capitis, Pediculus corporis andPediculosis pubis or Phthirus pubis, and the corresponding species wherean animal is the host).

Other Ingredients

An emulsion according to the invention may also comprise variouspharmaceutically or cosmetically acceptable excipients or additives suchas those which usually are employed in cosmetic or pharmaceuticalcompositions. Examples are pH adjusting agents such as buffers (such ase.g. citric acid, phosphate buffers, etc.), stabilizing agents (such ase.g. antioxidants like citric acid, sorbic acid, benzoic acid, ascorbicacid, tartaric acid, tocopherols, etc.), chelating agents (such as e.g.EDTA), preservatives (such as, e.g., phenoxyethanol, methylparaben,ethylparaben, propylparaben, butylparaben, sodium butylparaben, andmixtures thereof), flavouring agents, coloring agents, foaming agents,viscosity adjusting agents, thickening agents, spreading agents, pearlgloss agents, agents which protect the skin against aggressivesubstances in water, atmospheric air and on solid surfaces (examples ofsuch agents include salts, pigments, fats, esters etc.), agents whichhave an adstringent effect on the skin (e.g. Witch hazel extract,aluminium salts, etc.), agents which accelerate re-epithelialization ofthe skin or which are anti-irritants or anti-inflammatory substances(such as, e.g., bisabolol, sucralfate, LIPACIDE, gauaiazulene,poly-unsaturated fatty acid derivatives from plant seed oils and othervegetable sources, essential fatty acids and eicosanoids, extracts fromSea Whip Flutec (F 2 Chemicals, France), etc.), liposomes containingactive agents like α-hydroxy acids and other actives for the skin,humectants (such as, e.g., lanolin bases liposomal material, ureas,lactates, hydrolyzed proteins, glycerin, diglycerin, polyglycerin,PCA's, sorbitol, collagens, Shellac derivatives, 2-methyl-1,3-propanediol, etc.), protecting agents (such as, e.g. collagen, elastin,chitosan, salts, waxes, long chain alcohols, etc.). Other relevantadditives are:

Extracts such as the ones mentioned in combination with the first lipid,and such as, e.g., acacia extract, alfalfa extract, algae extract, aloeextract aloe vera gel, aloe vera gel condensed, althea extract, aniseextract, apple extract, apricot extract, apricot kernel oil, arnicaextract (arnica montana L), artichoke extract, asafoetida extract,avocado extract, azulene, balm mint extract, balm mint oil, bananaextract, barley extract, bee pollen extract, bioflavonoids, birch leafextract (betulla pendula rotl-L), black cohosh, black currant extract,black walnut extract, bladderwrack extract (fucus vesiculosos L), borageextract, botanical extracts, burdock extract (arctium lappa L), burnetextract, butcher's broom extract (ruscus aculeatus L), calendulaextract, camomile extract (matricaria charmomila L), caper extract,carrageenan extract, carrot extract (daucus carota L. var. sativa),carrot oil, centella (centalla asiatica urban), cherry bark extract,cinchona extract, cinquefoil extract, citroflavonoid water soluble,citrus bioflavonoid complex, clover blossom extract, coltsfoot extract,cornfrey extract, coneflower extract, cornflower extract (echinaceaangustifolia monch), corn silk extract, couch grass (agropyron repensbeauv.), crataegus extract (crataegus oxycantha L), cucumber extract,cypress extract, dandelion extract (taraxacum officinalis weber), elderflower extract, eleuterococcus, elm bark extract, ethyl alcohol (and)licorice extract, eucalyptus extract, everlasting extract, fennelextract, fenugreek extract (trigonella foenum-graecum L), fern extract,gardenia extract, garlic extract, gerrtian extract, gingko bilobaextract, ginko extract, ginseng extract (panax ginseng C. A. Meyer),glycyrrhetinic acid, glycyrrhizic acid, grape extract, grape leafextract, grape skin extract, guarana extract, Hawaiian ginger extract,hayflower extract, helichrysum (helichrysum italicum G. Don), hennaextract (lawsonia inermis), hesperidin complexes, hesperidin methylchalcone, hibiscus extract, hops extract (humulus lupulus L), horsechestnut extract (aesculus hippocastanum L), horsetail extract(equisetum arvenese L), hypericum extract, indian cress extract, ivyextract (hedera helix L), juniper extract (juniperus communis L), kelpextract, kiwi extract, laminaria extract, lavender extract, lemon balm(melissa officinalis L), lemon extract, lettuce extract, licoriceextract, linden extract (tilla argentea desf.), madder (rubia tinctorumL), mallow extract (malva silvestris L), matricaria extract English,milfoil extract (achillea millefolium L), mistletoe extract, mushroomextract, myrrh extract (commphora myrra (Nees), nettle extract (urticadiocia L), oak root extract, oat extract, onion extract orange blossomextract, orange flowers extract, pansy extract, parsley extract,pellitory extract, pennyroyal extract, peppermint extract (menthapiperita L), periwinkle extract, pine needle extract, plantain extract(plantago lanceolata), pollen extract, quince seed, rauwolfia extract,restharrow extract, rhatany extract (krameric triandra ruix et pav.),rhubarb root extract, rice bran extract, rose hips extract, rosemaryextract (rosmarinus officinalis), sage extract (Salvia officinalis L),sambucus extract, sanguinaria root extract, saponaria extract, sea weedextract, soy extract, soy protein, soy sterol, spearmint extract, sulfurtar complex, sunflower extract, sweet clover extract, tea extract, teatree oil, thistle extract, thyme extract (thymus vulgaris), tomatoextract, tormentill extract, valerian extract, walnut extract (junglasregia L), water cress extract, wheat bran extract, wheat germ extract,white nettle extract, white willow bark extract, wild indigo, witchhazel extract (hamamelis virginia L), yarrow extract, and zedoary oil(and) ginger oil (and) cinnamon oil;

humectants like acetamide MEA, acetamido propyl trimonium chloride,calcium stearoyl lactylate, chitosan PCA, diglycerol lactate, ethylester of hydrolyzed silk, fatty quaternary amine chloride complex,glycereth-7, glycereth-12, glycereth-26, glycereth-4.5 lactate,glycerin, diglycerin, polyglycerin, honey, hydrolyzed fibronectin,lactamide MEA, lactamide N-(2-hydroxyetheryl), mannitol, methylgluceth-10, methyl gluceth-20, methylsilanol PCA, panthenol, PCA, PEG-4,PEG-8, polyamino sugar condensate, quaternium-22, sea salts, sodiumcapryllactylate, sodium hyaluronate, sodium isostearoyl lactylate,sodium lactate, sodiumlauroyl lactylate, sodium PCA, sodiumpolyglutamate, sodium stearoyl lactylate, soluble collagen, sorbitanlaurate, sorbitan oleate, sorbitan sesquiisostearate, sorbitan stearate,sorbitol, sphingolipids, TEA-PCA;

moisturizers such as, e.g., aloe vera gel, aloe vera gel condensed, aloevera gel freeze-dried powder, aloe vera gel oil extract, amino acid,amniotic fluid, avocadin, calcium protein complex, cashew oil, chia oil,chitin, chitosan, chitosan PCA, cholesteric esters, chondroitin sulfate,collagen, collagen amino aids, copper protein complex, dioctyl maleate,dipentaerythritol fatty acid ester, elastin, ethyl panthenol, eveningprimrose oil, glycereth-12, glycosphingo lipids, honey, hyaluronic acid,hybrid safflower oil, hydrogenated polyisobutene, hydrolyzed collagen,hydrolyzed elastin, hydrolyzed fibronectin, hydrolyzedmucopolysaccharides, hydrolyzed silk, hydrolyzed wheat protein, jojobaesters, keratin amino acids, kiwi fruit extract, lactamide MEA, lanolinalcohol, liposomes, live yeast cell derivative liposome, marinapolyaminosaccharide, mineral oil, mink oil ethyl ether,mucopolysaccharides, mucopolysaccharides, palmetto extract, pantethine,paraffin, PEG-4, PEG-6,- PEG-8, PEG-12, PEG-100 stearate,perfluoropolymethyl-isopropyl ether, petrolatum, petroleum wax,pistachio oil, placenta extract, plankton extract, polyamino sugarcondensate, polybutene, polyglyceryl methacrylate, polypentaerythrityltetralaurate, PPG-10 butanediol, PPG-20 methyl glucose ether distearate,royal jelly extract, saccharide isomerate, selenium protein complex,serum albumin, sodium hyaluronate dimethylsilanol, sodium lactatemethylsilonol, sodium mannuronate methylsilanol, soluble collagen, superoxide dismutase, super oxide dismutase liposome, tissue extract,tocopheryl linoleate;

other skin protectants such as, e.g., allantoin, aloe vera gel, aniseextract, avocado oil unsaponifiables, carboxymethyl chitin, chondroitinsulfate, collagen, collagen amino acids, embryo extract, glycerylricinoleate, hydrolyzed animal elastin, hydrolyzed milk protein,hydrolyzed vegetable protein, linoleic acid (and) linolenic acid (and)arachidonic acid, liposomes, perfluoropolymethyl-isopropyl ether,plankton extract, and spine marrow extract.

An emulsion of the invention may further comprise active agents such asdisinfectants or antiseptics, drug substances including vitamins.Incorporation of one or more disinfectants or antiseptics is especiallyuseful in those situations where it is important to inactivate themicroorganisms which remain on the skin after normal cleansing.Incorporation of a drug substance is of special interest in connectionwith application of drug substances to the skin for the prevention ortreatment of various skin disorders or in connection with drugsubstances which advantageously are administered topically forpercutaneous absorption. The disinfectant and/or drug substance shouldpreferably have a solubility in the oily phase which secures that thesubstance is delivered to the skin in an effective amount.

In those cases where a disinfectant or antiseptic and/or a drugsubstance is present in an emulsion according to the invention, theconstitution of the oily phase of the emulsion may be determined usingsolubility parameters to predict the solubility of thedisinfectant/antiseptic/drug substance in the oily phase. Application ofsolubility parameters is described e.g. in Shell Chemical: TechnicalBulletin ICS(x)/75/1, in Hansen, C. M.: “The absorption of liquids intothe skin” UDK No. 66.062 published by Scandinavian Paint and PrintingInk Research Institute, and in Barton, A. F. M.: “CRC Handbook ofSolubility Parameters and Other Cohesion Parameters”, CRC Press Inc.,Florida.

Examples of suitable disinfectants and antiseptics are ambazone,bithionol, bromsalans, dibromsalan, metabromsalan, tribromsalan,cethexonium bromide, chlorhexidine acetate, chlorhexidine gluconatesolution, chloroazodin, chlorocresol, chlorothymol, chloroxylenol,clorophene, cresol, dichlordimethylhydantoin, dichlorobenzyl alcohol,dichloroxylenol, dofamium chloride, domiphen bromide, ethacridinelactate, methylbenzethonium chloride, nitromersol, noxythiolin, andtriclosan. Other relevant examples are sodium pyrithione, sodiumricinoleate, thimerosal, trichlocarban, undecylenamidopropyltrimethylammonium methosulfate, undecylenic acid, zinc pyrithione, and zincundecylenate.

The expression “drug substance” as used herein broadly includes anycompound, or mixture thereof, that is able to produce a beneficialeffect on the human to whom the drug substance has been given. Thus,drug substances include any physiologically or pharmacologicallysubstance that produces a localized or systemic effect in mammalsincluding humans. Examples of drug substances are found in manytherapeutic groups including antiinflammatory drugs, analgesics,tranquilizers, cardiac glycosides, narcotic antagonists,antiparkinsonism agents, antidepressants, antineoplastic agents andimmunosuppressants, antiviral agents, antibiotic agents, appetitesuppressants, antiemitics, antihistamines, antimigraine agents,coronary, cerebral or peripheral vasodilators, antianginals, calciumchannel blockers, hormonal agents, contraceptive agents, antithromboticagents, antihypertensive agents, chemical dependency drugs, localanaesthetics, corticosteroids, dermatological agents, and the like,vitamins like vitamin A such as all-trans retinol, retinol acetate,retinol palmitate, retinol propionate, betacarotene, halibut-liver oil,shark-liver oil, vitamin B₁ such as e.g. thiamine hydrochloride,benfotiamine, bisbentiamine, bisbutiamine, bisibutiamine, betoiaminehydrochloride, cetotiamine hydrochloride, cocarboxylase, cycotiamine,fursultiamine, vitamin B₂ such as e.g. riboflavine, riboflavinetetrabutyrate, flavine adenine dinucleotide, vitamin B₆, vitamin B₁₂such as e.g. cobalamins, B₁₂TAM, cobamamide, cyanocobalamin,mecobalamin, other vitamins of the B group, vitamin C such as e.g.ascorbic acid, vitamin D such as e.g. ergocalciferol (vitamin D₂),cholecalciferol (D3), 25-hydroxy-cholecalciferol or calcifediol,1,25dihydroxycholecalciferol or calcitriol, 1α-hydroxycholecalciferol oralfacalcitriol, dihydrotachysterol, alfacalcidol, calcifediol,calcitriol, cholecalciferol, cod-liver oil, dihydrotachysterol,ergocalciferol, vitamin E, alpha tocopherols, tocopheryl nicotinate,tocopherylquinone, wheat-germ oil, vitamin K such as e.g.phytomenadione, menadiol sodium diphosphate, menadione, vitamin P.

A very interesting group of drug substances are sucrose sulfate esterssuch as sucralfate, sucrose octasulfate and salts, esters and complexesthereof. Most suitably the sucrose sulfate esters or derivatives thereofare soluble in the oily phase of an emulsion according to the invention.

Other interesting substances which may be incorporated in an emulsionaccording to the invention are sunscreens and/or WV-absorbers, insectrepellants, and/or anti-parasitic agents against parasites like lice,fleas, scabies, bugs, and mites.

Examples of relevant sunscreens are allantoin, PABA, p-aminobenzoates,benzophenone-2, benzophenone-6, benzoresorcinol, benzyl salicylate,cinoxate, dioxybenzone, esculoside, ethyl4-bis(hydroxypropyl)aminobenzoate, ethylhexyl p-methoxycinnamate,etocrylen, glyceryl aminobenzoate, homosalate, methyl salicylate, methylanthranilate, methyl eugenol, 3-(4-methylbenzylidene)boran-2-one,mexenoe, octabenxone, octocrylene, oxybenzone, padimate,2-phenyl-1H-benzimidazole-5-sulphonic acid, and sulisobenzone. Otherrelevant sunscreens or UV-absorbers are: sunscreens like 3-benzylidenecamphor, coffee extract, ethyl salicylate, glyceryl PABA, homosalate,isopropylbenzylsalicylate, menthyl anthranilate, nylon-12 (and) titaniumdioxide, octyl dimethyl PABA, octyl methoxycinnamate, octyl salicylate,octyl triazone, orizanol, PEG-25 PABA, TEA-salicylate, titanium dioxide,zinc oxide; UV-A absorbers like benzophenone-1, benzophenone-3,benzophenone-4, bensophenone-8, benzophenone-9, benzophenone-11,benzophenone-12, butyl methoxydibenzoylmethane, 4-isopropyl dibenzoylmethane, and avocadin; and UV-B absorbers like argana oil,DEA-methoxycinnamate, drometrizole, ethyl dihydroxypropyl p-aminobenzoicacid, etocrylene, isopropyl methoxycinnamate,3-(4-methylbenzylidene)-camphor, octocrylene, octrizole, octyl dimethylPABA, octyl methoxycinnamate, octyl salicylate, octyl triazone, PABA,shea butter ethoxylated, TEA-salicylate, tri-PABA-panthenol.

Examples of relevant insect repellents are butopyronoxyl,butylethylpropanediol, dibutyl phthalate, diethyltoluamide, dimethylphthalate, and ethohexadiol. The concentration of the active drugsubstance—when present—in the emulsion depends on the active substancein question, its potency, the severity of the disease to be prevented ortreated, the age and condition of the patient. Methods applicable toselecting relevant concentrations of active substance in the emulsionare well known for a person skilled in the art and may be performedaccording to established guidelines for good clinical practice (GCP) orInvestigational New Drug Exemption (“IND”) regulations as described ine.g. Drug Applications, Nordic Guidelines, NLN Publication No. 12,Nordic Council on Medicines, Uppsala 1983 and Clinical Trials of Drugs,Nordic Guidelines, NLN Publication No. 11, Nordic Council on Medicines,Uppsala 1983. A person skilled in the art would by use of methodsdescribed in standard textbooks, guidelines and regulations as describedabove as well as common general knowledge within the field be able toselect the exact dosage regimen to be implemented for any selectedactive substance and dosage form using merely routine experimentationprocedures.

In a further aspect, the invention relates to a method for thepreparation of an emulsion. An emulsion according to the invention maybe prepared using procedures which are well known for a person skilledin the art. In the experimental section examples of a preparation of anemulsion according to the invention are given.

In a further, aspect the invention relates to an oil-in-water emulsioncomprising an oily phase at least part of which consists of atriglyceride having at least 90% of long chain C₂₀-C₂₂ fatty acids (seeabove for a detailed discussion). The emulsion is capable of separatinginto at least two distinct phases after standing for 24 hours whendiluted with tap water in a volume of 100 parts of water to one part ofthe emulsion at ambient temperature. The triglyceride typicallycomprises a combination of a monoenoic and a dienoic fatty acidcomponent, the ratio of the monoenoic fatty acid component to thedienonic fatty acid component being in a range corresponding to fromabout 1:99 to about 99:1 and the two unsaturated bonds of the dienoicfatty acid component being spaced from each other by at least 5 carbonatoms.

In other aspects, the invention relates to a method for cleansing orconditioning a skin surface, comprising applying, to the skin surface,

an emulsion comprising a skin-friendly oily phase and an aqueous phase,the emulsion being stabilized by containing at least onesurfactant/emulsifier,

and flushing the skin surface with a liquid, whereby the at least onesurfactant/emulsifier is substantially removed from the skin surfaceonto which the emulsion has been applied and thereby leaving at least apart of the oily phase on the skin.

In a still further aspect, the invention relates to a method fortreating human skin comprising applying, to the skin surface,

an emulsion comprising a skin-friendly oily phase and an aqueous phase,the emulsion being stabilized by containing at least onesurfactant/emulsifier, the at least one surfactant/emulsifier beingcapable of being substantially removed from a skin surface onto whichthe emulsion has been applied and from the emulsion by flushing with aliquid, thereby leaving at least a part of the oily phase on the skin,

until the transepidermal water loss (TEWL), determined as described inthe Examples, has decreased compared with the transepidermal water lossmeasured immediately before initiation of the treatment.

In still further aspects, the invention relates to i) Meadowfoam seedoil as a therapeutic agent, ii) use of Meadowfoam seed oil for themanufacture of a pharmaceutical composition for the treatment and/orprevention of mammalian parasites belonging to the phylum Arthropoda,iii) use of an oil-in-water emulsion for the treatment and/or preventionof mammalian parasites belonging to the phylum Artliropoda, iv) a methodfor treating mammals against parasites belonging to the phylumArthropoda, the method comprising administering to the mammal sufferingtherefrom an effective amount of Meadowfoam seed oil, v) a method fortreating mammals against parasites belonging to the phylum Arthropoda,the method comprising administering to an individual suffering therefroman effective amount of an oil-in-water emulsion, vi) use of Meadowfoamseed oil as a sun screen, vii) use of a combination of Meadowfoam seedoil and shea butter for the manufacture of a pharmaceutical compositionfor the treatment or prevention of mammalian parasites of the phylumArthropoda, vii) a method for protecting human skin against the sun, themethod comprising applying to the human skin an effective amount ofMeadowfoam seed oil alone or in combination with a vegetable extract,especially Karite extract, and viii) a method for protection of humanskin against the sun, the method comprising applying to the human skinan effective amount of an oil-in-water emulsion.

As will be understood, details and particulars concerning theabove-mentioned further aspects of the invention will be the same as oranalogous to the details and particulars concerning the emulsion aspectdiscussed above, and this means that wherever appropriate, thestatements above concerning the oil-in-water emulsion also apply to theother aspects of the invention.

Materials and Methods

In the following examples, the following materials are used (listed withthe INCI name and the CAS-No.):

CAS-No. INCI name available from Aqua 7732-18-5 Glyceroltricaprylate/caprate 65381-09-1 Unichema 3605 Glycerol ricinoleate1323-38-2 Grape seed oil 8024-22-4 J. Lorenzen, Denmark Meadowfoamtriglyceride 153065-40-8 The Fanning corporation Cocamide MEA 68140-00-1J. Lorenzen, Denmark Cocamidopropyl betaine 61789-40-0 GoldschmidtSulfated castor oil 8002-33-3 Henkel C9-11 Pareth 6 68439-46-3 BASFCitric acid 77-92-9 NDH, Denmark Tetrasodium EDTA 64-02-8 Dan-Chem,Denmark Phenoxyethanol 122-99-6 Methylparaben 99-76-3 Propylparaben94-13-3 Ethylparaben 12047-8 Butylparaben 94-26-8 Sodium butylparabeneMonoethanolamine Palm kernel fatty acid Rilanit GROM Nipabutyl sodiumNaHMF

The materials used were all of pharmaceutical, food or cosmetic grade.

The following methods are employed in the experimental section

Determination of Acid Value

The acid value gives the amount (in mg) of potassium hydroxide requiredto neutralize the free acids in 1 g of sample material.

In the present context, the acid value test may suitably be performed inorder to

i) determine the acid value of an oil-in-water emulsion according to theinvention;

ii) determine the acid value of the liquid which is used as a flushingmedium. In those cases where the content of free fatty acid in theoil-in-water emulsion is low or absent and where it is anticipated thatthe breaking of the emulsion by a flushing medium is insufficient, acompensation can be made by securing that the flushing medium (such as,e.g., water) has a suitable acid value (e.g. by adding free fatty acidor other acids to the flushing medium and, alternatively, also addingsalts (e.g. Ca²⁺ or Mg²⁺ salts), conditioning agents and/or flocculatingagents). During the cleansing/washing process 0.25-1% of the emulsion isnormally used in relation to the flushing medium. If the washing productdoes not contain any excess of free fatty acid then it can be calculatedthat the flushing medium should have an acid value in the range ofx/100-x/400, where x is the acid value normally aimed at for thecleansing/washing product itself in those cases where free fatty acid ispresent. Thus, if x=36, then the acid value of the flushing mediumshould be in a range corresponding to from about 0.1 to about 0.6;

iii) determine the content of free fatty acids in the liquid used, afterflushing the skin with a liquid upon application to the skin of anemulsion according to the invention. When the skin unto which anemulsion according to the invention has been applied is flushed with asuitable liquid, the emulsion separates into at least two distinctphases, i.e. an aqueous phase and an oily phase. Thus, the stabilizingeffect of the surfactant/emulsifier is reduced or even eliminated mostlikely due to a degradation of the surfactant/emulsifier. The liquid iscollected after flushing and the acid value is determined in the aqueousphase as well as in the oily phase in order to determine the content offatty acids in the at least two distinct phases.

The acid value is determined by use of a Mettler DL 25 titrator(Mettler, Denmark).

Before measurement of a sample, the titrator is calibrated using atleast 40 ml of each of two buffers having a pH of about 7.00 and 4.01,respectively. The calibration is performed in accordance with theinstructions given by the manufacturer. The acid value of a sample isthen measured by adding 40.0 ml of neutralized isopropyl alcohol to theamount of sample required for running the test (0.4-0.6 g).

An emulsion according to the invention should preferably have an acidvalue of about 10-60 mg KOH/g, such as, e.g., about 20-55 mg KOH/g,about 30-45 mg KOH/g, about 35-40 mg KOH/g or about 36.0-37.0 mg KOH/g.

Determination of pH

The pH of an emulsion according to the invention is determined byemploying a Mettler Delta 350 apparatus (Mettler, Denmark). Beforemeasurement of the pH of a sample, the apparatus is calibrated usingthree buffers having a pH of 7.00, 4.01 and 10.01, respectively. Themeasuring electrode A is a Mettler electrode Lot. 406-M6-DXX-57/25 andas reference electrode B a Mettler electrode Lot. U402-88TE-57/120 isused. A temperature sensor is placed in the buffer receiving themeasuring electrode, and the buffer receiving the reference electrode isstirred during calibration.

When the apparatus is calibrated, pH of a sample is measured in thefollowing manner.

A 50% pH value is determined by using 12 g of tap water mixed with 12 gof sample. The resulting mixture is cooled to about 17-18° C as thetemperature increases during measurement. The mixture is stirred. Duringmeasurement, stirring is performed at the reference electrode and the pHis measured according to the instructions given by the manufacturer.

A 100% pH value is determined by using a sample of an emulsion accordingto the invention and by cooling the sample to about 20° C. Stirring isperformed at the reference electrode and the pH measurement is performedin accordance with the instructions given by the manufacturer.

Determination of Viscosity

The viscosity is determined by means of a Brookfield DV 3 HA apparatusemploying a plate cone CP52, CP40 system as a spindle. The temperatureis kept constant during measurements (19.9-20.1° C.). Each sample issubjected to 10 individual measurements and the result given is theaverage thereof. In the table given below, the results of measurementsof an emulsion according to the invention are given.

Model: HA  Spindle: CP52 File: LJ_27  Sample: Plum Cleansing lotion Vis-Item Speed Torque cosity SH Stress SH Rate Temp Time # RPM % cP D/cm²1/s ° C. MM:SS 1 10.0 14.9 2929 585.9 20.0 20.0 00:20 2 10.0 15.0 2949589.8 20.0 19.9 00:20 3 10.0 15.1 2969 593.7 20.0 19.9 00:20 4 10.0 15.22988 597.7 20.0 19.9 00:20 5 10.0 15.3 3008 601.6 20.0 20.0 00:20 6 10.015.3 3008 601.6 20.0 20.0 00:20 7 10.0 15.4 3028 605.5 20.0 19.9 00:20 810.0 15.4 3028 605.5 20.0 19.9 00:20 9 10.0 15.4 3028 605.5 20.0 19.900:20 10 10.0 15.4 3028 605.5 20.0 19.9 00:20

Determination of Transepidermal Water Loss (TEWL)

Transepidermal water loss (TEWL) is a sensitive indicator of theintegrity of stratum corneum and can therefore be used as a measure ofskin barrier damages.

TEWL and evaporation of water from the surfaces are measured with aTewameter TM 20 (Courage+Khazaka electronic GmbH, Cologne, Germany).Important factors to consider during the measurements are airconvection, room temperature and ambient humidity. The guidelinesfollowed for the measurement of TEWL have been published by thestandardization group of the European Contact Dermatitis Society(Pippagoda, J., Tupker, R. A., Agner, T. and Serup, J. Guidelines fortranseuidermal water loss (TEWL) measurement. A report from thetandardization group of the European Contact Dermatitis Society. ContactDermatitis 1990, 22 164-178). The measurements were performed inaccordance with the instructions given by the manufacturer.

Determination of Skin Elasticity

Mechanical testing of skin is normally considered difficult, since theskin is a stratified composite material and the relationship between thevarious layers is complex.

Parameters used to describe skin mechanics are elasticity (see below),hysteresis (reflecting the creeping phenomenon) and distensibility (themaximum distension achieved).

Human skin is visco-elastic, i.e. it contains elastic as well as plasticcomponents. Elasticity is the ability of the skin to return to itsoriginal position after being stretched. A fully elastic skin surfacewill return to its original shape upon mechanical influence, whereas afully plastic skin does not return to its original shape upon mechanicalinfluence. Young skin, which is fresh and well-supplied with blood, isvery elastic. Aged skin, which is less supplied with blood, is moreplastic. Furthermore, various parts of the body have different degreesof elasticity and plasticity and different parts of the skin (i.e. skinon the cheek and the forehead) have different elasticity amplitudes.

The elasticity of the skin is measured by employing a Cutometer® SEM 575apparatus (Courage+Khazaka electronic GmbH, Cologne, Germany). Themeasurements are performed in accordance with the instructions given bythe manufacturer.

Determination of Skin Hydration by Means of Measurement of theElectrical Capacitance

As described in the description, the skin can be divided into two layerswhich seen from the skin surface are: the epidermis and the dermis.Stratum corneum is the outermost layer of the epidermis. Stratum corneumis of great importance for the moisture regulation of the skin. Stratumcorneum contains keratin, and what was once living epithelial cells havebecome horny scales that adhere tightly to one another, except at thesurface where they desquamate.

Another important layer within the epidermis is the stratum lucidumlayer which is present on e.g. human skin covering the body, except thepalms of the hands and the soles of the feet. The stratum lucidum hasspecial mechanical and chemical barrier functions. It forms a boundarylayer between the stratum corneum and the living cells of stratumgranulosum (another layer within the epidermis). Stratum lucidum alsoreacts to changes in humidity/moisture.

Skin moisture influences the formation of a water-sebum film. Such afilm forms the basis for the protective functions of the skin.Furthermore, only a moist skin has the desired optimal elasticity andprevents possible ageing signs. The so-called “aged skin” is relativelythin and usually dry and rough in texture. It also tends to wrinkle.Soaps, detergents, surfactants, emulsifiers, etc. are some of the causesof dry skin.

A measure for skin moisture can be obtained by employing a Corneometer®CM 820 (Courage+Khazaka electronic GmbH, Cologne, Germany). The methodis based on the fact that the dielectricity constants of water and othersubstances are different. The tests were performed in accordance withthe instructions given by the manufacturer.

Determination of Skin Sebum Content

Skin surface lipids from sebaceous glands and topically applied productsare quantified using an opaque lipid-sensitive plastic Mim. Whenattached to the skin, the film becomes transparent due to the content oflipids and the light transmission through the film is a measure of theamount of lipids per surface area units.

The skin sebum content was determined by employing a Sebumeter® SM 810(Courage+Khazaka electronics GmbH, Cologne, Germany). The tests wereperformed in accordance with the instructions given by the manufacturer.

Determination of Skin pH

Skin pH is a measure of the actual skin condition and skin quality. Theaverage pH value of human skin is about 5.5 for women and about 5 formen. The pH value depends on the tested skin area and various exogenicfactors. A pH value about 5-5.5 means that the pH of the skin is in theacidic range influencing the bactericidal and fungicidal effect of theskin.

Permanent treatment of the skin with e.g. soaps, cosmetics andpharmaceutical products or chemicals may lead to desiccation of the skinindicated by damages and premature ageing. Normally, soap solutions havepH values above 7. A healthy skin which is exposed to such a soapsolution will normally first regain its original pH value about 30minutes after exposure. A sensitive skin may adjust to a higher pH overa longer period of time which considerably influences its protectionfunctions. Furthermore, cosmetics which remain on the skin cause stressto skin, such as skin having an undesirably high pH value and, thus, theprotective function of the skin becomes reduced. pH on the skin can bemeasured in vivo by use on a non-invasive method employing e.g. aSkin-pH-meter® PH900 (Courage+Khazaka electronic GmbH, Cologne,Germany). The tests were performed in accordance with the instructionsgiven by the manufacturer.

Assessment of Dry Skin (Xerosis) and Ichthyosis

The assessment of dry skin is performed in accordance with theGuidelines published by The European Group on Efficacy Measurement ofCosmetics and other Topical Products (EEMCO) (J. Serup: Skin Researchand Technology 1995, 109-114).

EXAMPLES Example 1 Preparation of an Oil-in-water Emulsion According tothe Invention

A general method for the preparation of an emulsion according to theinvention is first to prepare the aqueous phase by mixing all thewater-soluble ingredients except the surfactant/emulsifier, e.g. in theform of a fatty acid, with purified water at 20° C. until theingredients are dissolved. The fatty acid is then added under a stirringprocess at ambient temperature to form a soap. After a reaction time ofabout 1 hour, the remaining ingredients are added one at a time andstirred thoroughly.

More specifically, an oil-in-water emulsion according to the inventionand having the composition mentioned below is prepared as described inthe following.

Composition of the oil-in-water emulsion:

Ingredients % w/w I: Aqua (purified) 57.94 Tetrasodium EDTA 0.31 Citricacid 0.50 MEA 99% 2.40 Potassium hydroxide 46% 0.16 II: Palmitic fattyacid 11.38 III: Glycerol tricaprylate/ 13.82 caprate Turkish red oil2.24 (sulfated castor oil) Parabene premix (mixture 0.73 of 70% w/wphenoxyethanol, 20% w/w methylparaben and 10% w/w propylparaben)Tegobetain F50 5.36 (cocoamidopropyl betaine) Meadowfoam seed 4.47triglyceride Lutensol TO3 0.69 (C9-11 Pareth) 6

The ingredients mentioned under I are mixed at 20° C. II is added undera stirring process to form a soap. After a reaction time of one hour,the ingredients mentioned under III are added one at a time and stirredthoroughly. pH of the resulting emulsion is 7.5-7.7 measured asdescribed above under the heading “Determination of pH”.

Example 2 Composition of Lotions According to the Invention

The ingredients in lotions according to the invention are given in thefollowing table. The preparation of the lotions was performed asdescribed in Example 1.

JL-30 was prepared by mixing the ingredients in the series given. Thepalm kernel fatty acid had a temperature of 50° C. Rilanit GMRO had atemperature of 37° C. The mixing process was performed at roomtemperature and the mixture was stirred at an increasing speed ofrotation followed by a homogenizing process. Stirring times are givenagainst an increase in minutes counted from the beginning of theprocess.

In the table, stability data are also given. Four series of stabilitytests were performed for samples in sealed containers stored at atemperature of −5° C., 20° C., 37° C. and 50° C., res The stability wasevaluated by visual inspection and a score of 0, 1 or 2 was given toeach sample after inspection. 0 refers to lotions which have separatedinto two distinct phases, 1 refers to lotions where no tendency ofseparation is observed, and 2 refers to lotions with tendency toseparate into two phases. The initial results show that lotionsaccording to the invention have a good physical stability with regard tothe stability of the emulsion formed.

JL-20 JL-20-1 JL-21 w/w w/w w/w Ingredients Water, cold, purified 60.54%60.32% 57.81% EDTA 40%^(a) 0.32% 0.32% 0.30% Citric acid^(b) 0.52% 0.52%0.48% MEA 99%^(c) 2.31% 2.30% 2.59% KOH 46% 0.16% 0.16% 0.19% Palm seedfatty acid^(d) 0.00% 0.00% 0.00% Coco fatty acid^(e) 11.72% 11.67%12.24% Grape seed oil^(f) 14.54% 14.45% 13.82% Turkish red oil^(g) 2.26%2.25% 2.16% Parabene premix^(h) 0.74% 0.66% 0.69% Tegobetain F50^(i)1.86% 1.84% 5.27% Meadowfoam seed oil^(j) 4.81% 4.84% 4.45% LutensolTO3^(k) 0.21% 0.67% 0.00% SUM: 100.00% 100.00% 100.00% pH: 6.990 7.5907.783 Acid value 35.85 37.41 Viscosity^(l) 1500 cp 4800 cp pH^(m)/acidvalue 6.944 7.783 Stability Test Acid value 36.6 37.41 Day 1 −5° C./20°C. 1/1 1/1 37° C./50° C. 1/1 1/1 Day 7 −5° C./20° C. 1/1 1/1 37° C./50°C. 1/2 1/1 Day 30 −5° C./20° C. 1/2 1/1 37° C./50° C. 0/0 1/1 Day 60 −5°C./20° C. 1/0 37° C./50° C. 0/1 Day 180 −5° C./20° C. 37° C./50° C.JL-22 JL-23 JL-24 w/w w/w w/w Ingredients Water, cold, purified 58.94%56.42% 52.20% EDTA 40%^(a) 0.31% 0.30% 0.37% Citric acid^(b) 1.05% 0.63%0.56% MEA 99%^(c) 2.23% 2.01% 2.49% KOH 46% 0.17% 0.15% 0.17% Palm seedfatty acid^(d) 0.00% 0.00% 0.00% Coco fatty acid^(e) 11.54% 11.13%14.02% Grape seed oil^(f) 14.40% 13.74% 15.50% Turkish red oil^(g) 0.00%2.15% 2.47% Parabene premix^(h) 0.72% 0.66% 0.81% Tegobetain F50^(i)5.74% 7.79% 6.11% Meadowfoam seed oil^(j) 4.53% 4.35% 5.02% LutensolTO3^(k) 0.37% 0.68% 0.00% SUM: 100.00% 100.00% 100.00% pH: 7.091 7.2497.261 Acid value 40.28 40.72 45.48 Viscosity^(l) 620 cp 2020 cp 187900cp pH^(m)/acid value 7.091 7.249 7.261 Stability Test Acid value 40.2840.72 45.48 Day 1 −5° C./20° C. 1/1 1/1 1/1 37° C./50° C. 1/1 1/1 1/1Day 7 −5° C./20° C. 1/1 1/1 1/1 37° C./50° C. 1/1 1/1 1/1 Day 30 −5°C./20° C. 1/1 1/1 1/1 37° C./50° C. 1/1 1/1 0/2 Day 60 −5° C./20° C. 37°C./50° C. Day 180 −5° C./20° C. 37° C./50° C. JL-25 JL-26 JL-27 w/w w/ww/w Ingredients Water, cold, purified 59.20% 57.94% 58.00% EDTA 40%^(a)0.30% 0.31% 0.30% Citric acid^(b) 0.52% 0.50% 0.50% MEA 99%^(c) 2.09%2.40% 2.42% KOH 46% 0.18% 0.16% 0.22% Palm seed fatty acid^(d) 0.00%11.38% 0.00% Coco fatty acid^(e) 11.75% 0.00% 11.36% Grape seed oil^(f)14.28% 13.82% 13.82% Turkish red oil^(g) 2.27% 2.24% 2.15% Parabenepremix^(h) 0.74% 0.73% 0.72% Tegobetain F50^(i) 5.58% 5.36% 5.29%Meadowfoam seed oil^(j) 2.30% 4.47% 4.50% Lutensol TO3^(k) 0.78% 0.69%0.72% SUM: 100.00% 100.00% 100.00% pH: 7.277 7.699 7.769 Acid value38.03 36.37 36.00 Viscosity^(l) 4900 cp 3330 cp 18600 cp pH^(m)/acidvalue 7.277 7.699 7.769 Stability Test Acid value 38.03 36.37 36.00 Day1 −5° C./20° C. 1/1 1/1 1/1 37° C./50° C. 1/1 1/1 1/1 Day 7 −5° C./20°C. 1/1 1/1 1/1 37° C./50° C. 1/1 1/1 1/1 Day 30 −5° C./20° C. 1/1 37°C./50° C. 0/2 Day 60 −5° C./20° C. 37° C./50° C. Day 180 −5° C./20° C.37° C./50° C. JL-30 JL-57-C Raw material % Raw material % Water, cold57.28 Water, cold 56.97 EDTA 40% 0.31 Citric acid 0.49 Citric acid 0.49MEA 99% 2.17 MEA 99% 2.27 KOH 46% 0.17 0.00 EDTA 40% 0.00 KOH 46% 0.150.00 Palm kernel 11.24 Palm kernel 11.24 fatty acid fatty acid 0.00Meadowfoam seed 4.39 Grape seed oil 13.65 Grape seed oil 13.58 Turkishred oil 2.18 Turkish red oil 2.19 Phenonip 0.66 0.00 Tegobetaine F505.29 Tegobetaine F50 5.30% Meadowfoam 4.44 seed 0.00 0.00 Sepacide HB20.77 0.00 Nipabutyl sodium 0.19 0.00 NaHMF 0.50 Rilanit GRMO 2.03Rilanit GRMO 2.04 SUM: 100.00 SUM: 100.00 pH: 7.559 pH: 7.384 Visc.6/10: 2230 cp Visc. 6/10 2520 cp Acid value 37.61 Acid value 34.30Stability/Name JL-30 JL-57-C Viscosity 2230 cp 2520 cp pH/acid No. 7.5597.384 Mf./ref. % Special Acid value 37.61 Acid value 34.30 Day 1 −5°C./20° C. 1/1 1/1 37° C./50° C. 1/1 1/1 Day 7 −5° C./20° C. 1/1 1/1 37°C./50° C. 1/1 1/1 Day 30 −5° C./20° C. 1/1 1/1 37° C./50° C. 1/1 1/2 Day60 −5° C./20° C. 1/1 37° C./50° C. 0/1 Day 180 −5° C./20° C. 1/1 37°C./50° C. 0/0 ^(a)chelating agent ^(b)stabilizing agent with respect tooxidation ^(c)monoethanolamine (part of the surfactant/emulsifierformed) ^(d,e,f)def part of the oily phase^(g)co-surfactant/co-emulsifier ^(h)preservative mixture of parabens^(i)co-surfactant/co-emulsifier (amphotheric substance) ^(j)lipid withgood adherence to the skin ^(k)co-surfactant/co-emulsifier ^(l)theapparent viscosity determined with a Brookfield Rheometer at 20° C.; theviscosity is aimed at being in a range of about 500-5,000 cp such asabout 1,000-4,000 cp, about 2,000-5,000 cp or about 3,000-4,000 cp^(m)pH is aimed at being in a range of about 7-8.5 such as about 7.7-7.9

Example 3 Oxidative Stability of a Cleansing Lotion According to theInvention

The oxidative stability of a sample of Batch JL-25 (see Example 2) wastested at Aarhus Olie, Aarhus, Denmark employing an Oxipress running at80° C. The results show that the sample is stable for about 31-32 hours.Then, the oxidation process stats and the stability decreases evenly.

Further tests have shown that substituting the fatty acids derived fromgrape seed oil with fatty acids derived fromglyceroltricaprylate/caprate or with CREMEOL PS6 results in a muchhigher stability of the cleansing lotion.

Example 4 Examination of the Ecotoxicity of a Cleansing Lotion Accordingto the Invention

According to e.g. the National Swedish Nature Conservancy Board (pubplSNV 1975:10) only degreasing agents should be used which at loadingtests according to IVL method 2 gives a mineral oil content of 100 mg/lor lower after 2 hours.

Testing according to the ST method of PLUM Washing lotion gives amineral oil content of <10 mg/l and the content is of the same order ofmagnitude compared with results obtained after testing of a blankcontaining plain water.

Example 5 Determination of the Fatty Acid Content in the Aqueous Phaseand the Oily Phase, Respectively, after Flushing with a Liquid

An accurate amount of a lotion according to the invention is applied towet hands and the hands are washed thoroughly for two minutes. The handsare then rinsed by flushing with 10 I of tap water having a hardnessdegree in the range of 5-30 degrees. The rinsing water is collected andallowed to stand for 0.5 hour in order to secure a complete separationinto two phases (the separation takes place substantially immediatelyupon flushing). The two layers are separated and the acid values of theoily phase and of the aqueous layer, respectively, are determined.

The results show that free fatty acids are predominantly present in theaqueous phase indicating that the emulgating properties of a fatty acidbased surfactant/emulsifier is destroyed during rinsing. Furthermore,the results indicate that the surfactant/emulsifier is substantiallycompletely washed off the hands during the rinsing period.

Example 6 Investigation of the Cleansing Effect of a Lotion According tothe Invention and of the Effect on the Skin

An oil-in-water emulsion in the form of a lotion and having thecomposition stated below was tested in vivo on workers atSlagteriskolen, Roskilde, Denmark.

JL-28 Ingredients w/w Water, cold, purified 57.94% EDTA 40%^(a) 0.31%Citric acid^(b) 0.50% MEA 99%^(c) 2.40% KOH 46% 0.16% Palm seed fattyacid^(d) 11.38% Glycerol tricaprylate/caprate^(f) 13.82% Turkish redoil^(g) 2.24% Parabene premix^(h) 0.73% Tegobetain F50^(i) 5.36%Meadowfoam seed oil^(j) 4.47% Lutensol TO3^(k) 0.69% SUM: 100.00%

The following washing instructions were given:

Wash after work

Purpose:

To loosen and wash off microorganisms

Product:

Plum Cleansing lotion

Instructions for use:

Flush hands with water. Apply one squeeze of lotion.

Work lotion thoroughly with hands for 20 seconds. Add water, rinse anddry hands.

The evaluation of the acceptance and effect of the cleansing lotionaccording to the invention is based on the following questionnaire andon personal interviews with the users (see below).

Furthermore, the evaluation is based on determination of TEWL,capacitance and elasticity as described above.

Questionnaire for Plum Cleansing lotion

How does it feel to wash with the product? Pleasant Good Not so goodUnpleasant How is the cleansing effect? Outstanding Good Not so goodPoor Was the product easy to rinse off? Yes No What effect does theproduct have after it has been rinsed off compared to the soap you areusing today? Less desiccating The same More desiccating Do you have dryhands already? Yes No What do you think of the product - overall? GoodPoor

Own comments:

Evaluation of liquid soap/cleansing lotion/96—personal interviews

Grades: 1-5, 1=good 5=poor or comments

Product: LJ-19 Person evaluating:

Comments Grade 1 2 3 4 5 ? Immediately felt effect of the productAbility to spread on wet hands Foamablity in wet washing Rinsingcharacteristics Effect felt on skin immediately after washing Effectfelt on skin immediately after drying Effect felt on skin five minuteslater Comments, if any

Results

The following general points should be noted from the answers obtainedat the slaughterhouse:

The foaming property of the product is relatively low compared to thatof normal soap. The users who can accept this fact express that theirimmediate impression of the product is good, that it is easy to spreadand dilute on the skin, and that it is easy to rinse off. The cleansingeffect is good and even if there is a lot of grease on the skin, this iseasily washed off—at least as easily as when using a strong soap.Immediately after washing and later, the experience of the hands israted high: as average—and mainly above.

In particular those persons working with areas involving a lot of wateror a humid environment and who have a tendency to have dry skin,normally have a high preference for such a product that really bringsback fat to the skin in connection with the washing process.

A survey at four hospitals—79 responses—(with a slightly differentquestionnaire) clearly showed that many of the employees with a tendencyto have dry skin preferred washing lotion over an liquid soap of goodquality.

Example 7 Comparative Testing of POLO SPORT WOMAN® by RALPH LAURENS anda Cleansing Lotion According to the Invention

As mentioned on the package of POLO SPORT WOMAN® 200 ml it contains thefollowing ingredients:

water, sodium laureth sulfate, Meadowfoam seed oil, sorbitanmonoisostearate, PEG-6 caprylic/capric glycerides, fragrance, glycerin,cocamide MEA, muristic acid, disodium cocoamphodiacetate, sea fennel,extract, sea rocket extract, pacific sea kelp extract, algae extract,tocopherol acetate, propylene glycol, cocamidopropyl betaine,phenoxyethanol, guar hydroxypropyltrimonium chloride, methylparaben,propylparaben, disodium EDTA. No specific composition is given and,therefore, in order to document that this composition from Ralph Laurensis different from a composition according to the present invention, theRalph Laurens washing product and a composition according to theinvention have been subjected to the tests given in the following.

The washing product according to the invention had the composition givenin Example 2 under the heading “JL-30” (in this example also denotedPLUM Washing lotion):

Tests performed:

i) TEWL (transepidermal water loss) has been performed using theantecubital fossa (flex area of elbow). The antecubital fossa isespecially suited to washing tests because the skin is thin and elasticand contains stratum corneum as well as stratum lucidum. Furthermore,due to the inventors' experience a washing test using the antecubitalfossa gives very good and reproducible results for a fairly large areaof the skin. In particular a good reproducibility is observed withregard to TEWL.

ii) Determination of sebum content before and after the washingprocedures by means of a Sebumeter

iii) Measurement of the skin moisture by means of a Corneometer

iv) Separation test of the compositions after dilution with tap waterhaving the following composition:

Test Result pH 7.8 Conductivity 75 mS/m Permanganat value KMn04 2.8 mg/lEvaporation residue 470 mg/l Calcium 120 mg/l Magnesium 10 mg/lHardness, total 18.9 degrees dH Sodium 26 mg/l Potassium 2.7 mg/lAmmoniak + ammonium 0.01 mg/l Iron 0.005 mg/l Mangan 0.01 mg/lHydrocarbonate 320 mg/l Chloride 45 mg/l Sulfate 65 mg/l Nitrate 1 mg/lNitrite 0.005 mg/l Phosphor, total-P 0.02 mg/l Fluoride 0.22 mg/l Oxygencontent 7 mg/l Carbondioxide, aggr. 2 mg/l Nickel 1.8 microg/l

The elbow washing test is performed using two different products; onefor the right and one for the left elbow.

Applied procedure:

The antecubital fossa is rinsed/wetted under running aqua communes(water analysis, se above) of a temperature of approx. 20° C. Then 1 gof washing product is added. The washing product is worked with thesecond and third finger of the other hand in soft circular movements for20 sec over an area of approx. 20 cm². Next, running water is addedunder continuous working, and the product is thoroughly rinsed off withthe running water of 20° C. The washing process is completed after 30-35sec. Afterwards, soft cloth is used for dabbing.

Measurements of the skin are undertaken before the first washing, after10th, 20th and 40th washing. All skin measurements are performed onconditioned skin—after a pause of at least 30 min.

Previous experiences:

When using an ordinary liquid soap, no lipid or nearly no lipid willmeasure on the skin (Sebumeter) Measuring value: 0.

Provided that prior to washing TEWL is approx. 11, the TEWL after 20washings will increase to 13-18 when using an ordinary liquid soap.

However, as is seen from the results below, TEWL does not increase inthe case of PLUM Washing lotion.

Comparative measurements Left bend of arm Right bend of arm Item POLOSPORT WOMAN ® PLUM Washing lotion Before washing TEWL 11.3 11.3 g/m²hSebumeter  2  2 Corneometer 60-90 60-95 After 10 washings TEWL 11,8 10Sebumeter  0  3 Corneometer 65-90 65-90 After 20 washings TEWL 11.3 11Sebumeter  0  4 Corneometer 60-85 55-85 After 40 washings TEWL 14 10Sebumeter  1  6 Corneometer 55-85 60-85

The above measurements clearly demonstrate that PLUM Washing lotionleaves the lipid on the skin in a considerable amount—approx. an amountequalling the natural amount of lipid on the skin.

Comparing these test results to the results of separation tests forwashing lotions clearly demonstrates that the ability of PLUM Washinglotion to separate the oil in a 1% solution (the normal water dilutionin a washing process where water consumption is sparse) also in practiceis demonstrated by the fact that lipid is left on the skin.

Results of Separation Test

1% w/w dilution (1 g of washing product is diluted to 100 g with aquacommunis having a hardness degree of about 18 degrees)

POLO SPORT PLUM Washing WOMAN ® lotion after 1 min. homogenous separatedafter 1 hour homogenous separated after 4 hours homogenous separatedafter 24 hours homogenous separated

Upon dilution with distilled water, all corresponding 1% dilutionsremained stable for 24 hours.

In conclusion, the washing product POLO SPORT WOMAN® does not fulfil therequirements claimed in connection with the present invention and,furthermore, its ability to leave lipid on the skin is decreasedcompared with PLUM Washing lotion.

Example 8 Separation Tests of POLO SPORT WOMAN® and PLUM Washing Lotion

In the following results are given from separation and stirring tests ofthe washing products from Example 7. From the results it is clear thatPLUM Washing lotion quickly separates into two distinct phases whendiluted with plain water, i.e. water having a degree of hardness of fromabout 8 to about 25 degrees, and when a dilution with water of thewashing product is 1 g of the washing product to a total of 100 g, i.e.a dilution which is relevant for practical use. In contrast, POLO SPORTWOMAN® does not separate under these conditions.

Moreover, it is seen that when distilled water is used, no separationoccurs within 24 hours. These results support that ions like Ca²⁺ andMg²⁺ present in plain water play an important role in the separationprocess.

Based on the results given below and the results given in the Examplesabove, it is concluded that PLUM Washing lotion has unique propertieswith respect to its ability of separate into an oily and an aqueousphase and, thus, it enables a part of the oily phase to remain on theskin or wherever it is applied (e.g. on the hair) while maintaining itscleansing effect.

POLO SPORT WOMAN ® PLUM Washing lotion Test No. 5A/7A Concentration 1%1% Diluted with plain water plain water Visually inspected after; 5 minhomogenous separated with white cream 2 mm 15 min homogenous separatedwith white cream 2 mm 30 min homogenous separated with white cream 2 mm60 min homogenous separated with white cream 2 mm Test No. 5B/7BConcentration 1% 1% Diluted with plain water plain water Visuallyinspected after; 5 min homogenous separated with white cream 2 mm 15 minhomogenous separated with white cream 2 mm 30 min homogenous separatedwith white cream 2 mm 60 min homogenous separated with white cream 2 mmTest No. 6A/8A Concentration 1% 1% Diluted with distilled waterdistilled water Visually inspected after; 5 min homogenous homogenous 15min homogenous homogenous 30 min homogenous homogenous 60 min homogenoushomogenous Test No. 6B/8B Concentration Diluted with distilled waterdistilled water Visually inspected after; 5 min homogenous homogenous 15min hornogenous homogenous 30 min homogenous homogenous 60 minhomogenous homogenous

Viscosity determination of JL-30 Vis- Shear Speed Torque cosity StressShear Rate Temperature Time RPM % cP D/Cm² 1/sec ° C. sec 0.1 0.917694.0 35.4 0.20 20.1 22.0 0.2 1.0 9830.0 39.3 0.40 20.1 20.5 0.3 1.27864.0 47.2 0.60 20.2 20.9 0.5 1.4 5504.8 55.0 1.00 20.1 20.6 1.0 1.83538.8 70.8 2.00 20.1 20.6 1.5 2.1 2752.4 82.6 3.00 20.1 20.6 2.0 2.42359.2 94.4 4.00 20.1 20.6 2.5 2.7 2123.3 106.2 5.00 20.1 20.6 3.0 2.91900.5 114.0 6.00 20.1 20.6

Example 9 Cleansing Test of Plum Washing Lotion and POLO SPORT WOMAN®

The above products' cleansing properties were tested on a standard ofdirt (thin). The plates were covered with a standard of dirt and left todry for four weeks at 30° C. A standard of dirt consists of 1% carbonblack in the mineral motor oil Shell Super.

The test was carried out as follows:

1. 1.5 g of cleansing product was added and spread on to the plate

2. Light washing with a brush for 30 sec. following which luke warmwater was added, and then washing with a brush was continued again for30 sec.

3. The plate was left to dry

4. Evaluation of the results.

Score Score Name Special solubility rinsability Other Plum Washinglotion tube 2.0 2.0 POLO SPORT WOMAN ® std. 3.0 3.0

Scores given between 1 and 5 where 1 corresponds to a very finecleansing effect and 5 to an unacceptable cleansing effect.

Example 10 Effect of Plum Washing Lotion Against Lice

Human clothing lice, Pediculus humanus, were obtained from the culturecolony maintained by the Medical Entomology Centre. Adult lice used inthe test were mixed male and females that were fed not less than fourhours before exposure to the test product. The resting period afterfeeding is allowed to permit the insects to excrete fluid from theirblood meal and reduce mortality from handling.

Adult lice were counted into three replicate batches of twenty-one foreach test, allowing for any that may be lost through washing. The licewere provided with a gauze substrate to stand on during the tests.

For the test the lice were exposed to the product mimicking as closelyas possible use by consumers as follows;

The lice were washed with a 1:15 solution Plum Washing lotion and thenexposed to the experimental formulation for 10 minutes, during which thegauze was turned over to ensure even coverage. They were then washed andrinsed in a 1:15 solution of Plum Washing lotion and three changes oftap water (35° C.) twice before being blotted dry, using a medical wipetissue and incubated under normal maintenance conditions until theresults were recorded after 24 hours.

What is claimed is:
 1. An oil-in-water emulsion for application on askin surface, the emulsion comprising an oily phase and an aqueousphase, said oily phase comprising a first lipid of vegetable or animalorigin, the emulsion being stabilized by containing at least onesurfactant/emulsifier, the at least one surfactant/emulsifier beingsubstantially removed from a skin surface onto which the emulsion hasbeen applied and from the emulsion by flushing with liquid, therebyleaving at least a part of the oily phase on the skin, and the emulsionwhen diluted with tap water having a degree of hardness of about 18degrees in a volume of 100 parts of water to one part of the emulsion atambient temperature, being separated into at least two distinct phasesafter standing for 24 hours at ambient temperature, wherein theoil-in-water emulsion has a pH value of at least 6, and at least about50% w/w of the total concentration of the at least onesurfactant/emulsifier which is a fatty acid derivative, wherein saidderivative has a fatty acid component which is a saturated orunsaturated C₁₀-C₂₄ hydrocarbon carboxylic acid or mixtures thereof. 2.An emulsion according to claim 1, wherein the emulsion comprises atleast 1% w/w of the first lipid which has good adherence to the skin. 3.An emulsion according to claim 2, wherein the first lipid is a lipidwhich has such a water retention ability that 1 g of the lipid canretain at least 2 g of water at ambient temperature.
 4. An emulsionaccording to claim 3, wherein the first lipid is selected from the groupconsisting of Meadowfoam seed oil, shea butter (Karite butter), cocoabutter, lanolin, and mixtures thereof.
 5. An emulsion according to claim2, wherein the first lipid is a triglyceride comprising at least 90% oflong chain C₂₀-C₂₂ fatty acids.
 6. An emulsion according to claim 5,wherein the triglyceride comprises a combination of a monoenoic and adienoic fatty acid component, the ratio of the monoenoic fatty acidcomponent to the dienonic fatty acid component being in a rangecorresponding to from about 1:99 to about 99:1 and the two unsaturatedbonds of the dienoic fatty acid component being spaced from each otherby at least 5 carbon atoms.
 7. An emulsion according to claim 5, whereinthe triglyceride is Meadowfoam seed oil.
 8. A emulsion of claim 1wherein the at least one surfactant/emulsifier is a fatty acidderivative selected from the group consisting of sodium salts, potassiumsalts, ammonium salts, substituted ammonium salts, unsubstituted amides,amides with substituted amines, monoethanolamides, diethanolamides,triethanolamides, propanolamines, and isopropanolamides, and mixturesthereof.
 9. An emulsion of claim 1 wherein the fatty acid component isselected from the group consisting of capric acid (C₁₀H₂₀O₂),undecylenic acid (C₁₁H₂₂O₂) lauric acid (C₁₂H₂₄O₂), myristic acid(C₁₄H₂₈O₂), palmitic acid (C₁H₃₂O₂), stearic acid (C₁₈H₃₀O₂), arachidieacid (C2₀H₄₀O₂), behenic acid (C₂₂H₄₄O₂), and lignoceric acid(C₂₄H₄₈O₂), and mixture, thereof.
 10. An emulsion of claim 1 wherein thefatty acid component is selected from the group consisting ofpalmitolcic acid (C₁₆H₂₀O₂), olcic acid (C₁₈H₃₄O₂), claidic acid(C₁₈H₃₄O₂), crucic acid (C₂₂H₄₂O₂), and brassidic acid (C₂₂H₄₂O₂), andmixtures thereof.
 11. An emulsion of claim 1 further comprising anadditional surfactant/emulsifier having an HLB value of from about 4 toabout
 30. 12. An emulsion of claim 1 wherein the total concentration ofsurfactant/emulsifier in the emulsion is from about 10 to about 35 %w/w.
 13. An emulsion of claim 1 wherein the acid value of the emulsionis in a range of from about 25 to about
 45. 14. An emulsion of claim 1wherein the pH of the emulsion is from about 7.0 to about 8.0.
 15. Anemulsion of claim 1 wherein the pH of the emulsion is from about 7.2 toabout 7.8.
 16. An emulsion of claim 1 wherein the oily phase comprises asecond lipid selected from vegetable fats and animal fats.
 17. Anemulsion of claim 1 wherein the oily phase comprises a second lipid thatis a vegetable fat selected from the group consisting of avocado oil,coconut fat, cocoa butter, rapeseed oil, maize oil, sesame oil, oliveoil, soybean oil, palm oil, grape seed oil, almond oil, linseed oil,peanut oil, walnut oil, tall oil, thistle seed oil, wheat germ oil,sunflower oil, poppy seed oil, cottonseed oil, persic oil, apricot oil,jojoba oil, castor oil, hydrogenated vegetable oils, CREMEOL PS 6, POS,and PSW, and mixtures thereof.
 18. An emulsion of claim 1 wherein theoily phase comprises a second lipid that is a vegetable fat derived fromplant species from the family Limnanthaceue.
 19. An emulsion of claim 1wherein the oily phase comprises a second lipid that is a vegetable fatderived from plant species of Limnathes alba.
 20. An emulsion of claim 1wherein the oily phase comprises a second lipid selected from mono-, di-and triglycerides.
 21. An emulsion of claim 1 further comprising a drug.22. An emulsion of claim 21 wherein the drug is a vitamin.
 23. Anemulsion of claim 1 wherein the oily phase comprises meadowfoam seed oiland Karite butter extract or Karite extract.
 24. An emulsion of claim 2wherein the first lipid is mixed with an extract selected from the groupconsisting of Kante butter extract, karite extract, aloe barbadensisextract, apricot extract, arnica montana extract, balm mint extract,bamboo extract, bearberry extract, beet extract, bilberry extract, birchleaf extract, blackberry leaf extract, bladderwrack extract, buckwheatextract, burdock extract, butcherbroom extract, calendula extract,carrot extract, matricaria extract, cherinmoya extract, jujube extract,coltsfoot extract, comfroy extract, coneflower extract, balsam copaiba,cornflower extract, cucumber extract, dog rose hips extract, fennelextract, ginger extract, ginkgo extract, ginseng extract, camelliasinensis extract, guarana extract, cratacgus monogina extract, hayflowerextract, henna extract, hops extract, horsetail extract, horsechesnutextract, hydrocotylextract, ivy extract, Job's tears extract, juniperuscommunis extract, kiwi extract, lady's mantle extract, laminariadigitata extract, lavender extract, lemon peel extract, licoriceextract, linden extract, lithospermum officinale extract, mallowextract, mango extract, marshmallow extract, melon extract, mimosatenuiflora bark extract, white oak bark extract, English oak extract,oyster shell extract, pansy extract, peach extract, capsicum frutescensoleoresin, capsicu frutescens extract, peppermint extract, quillajasaponaria extract, raspberry extract, krameria triandra extract,rosemary extract, sage extract, St. John's wort extract, stinging nettleextract, strawberry extract, soapwort extract, thyme extract, walnutextract, watercress extract, wheat germ extract, willow bark extract,and witch hazel extract.
 25. A method for cleansing or conditioning askirt surface, comprising applying, to the skin surface, theoil-in-water emulsion of claim 1, and flushing the skin surface with aliquid, whereby the at least one surfactant/emulsifier is substantiallyremoved from the skin surface onto which the emulsion has been appliedand thereby leaving at least part of the oily phase on the skin.
 26. Amethod for treating human skin comprising applying, to tho skin surface,the oil-in-water emulsion of claim 1, and flushing the skin surface witha liquid, whereby the at least one surfactant/emulsifier issubstantially removed from the skin surface onto which the emulsion hasbeen applied and thereby leaving at least part of the oily phase on theskin, said treating decreasing transepidermal water loss as comparedwith transepidermal loss measured immediately before initiation of thetreating.
 27. A method for treating mammals against parasites belongingto the phylum Arthropoda, the method comprising applying to skin of amammal suffering therefrom an effective amount of an oil-in-wateraccording, to claim
 1. 28. A method for protection of human skin againstthe sun, the method comprising applying to the human skin a protectiveeffective amount of an oil-in-water emulsion according to claim
 1. 29.An emulsion according to claim 1 further comprising an active agentselected from disinfectants, antiseptics and drug substances.
 30. Anemulsion according to claim 29 comprising an active agent selected fromdisinfectants and antiseptics.
 31. An emulsion according to claim 29wherein the active agent is a drug substance.
 32. An emulsion accordingto claim 1 further comprising a substance selected from sunscreens, UVabsorbers, insect repellants, and anti-parasitic agents.